From Wikipedia, the free encyclopedia
The tables contain the prime factorization of the natural numbers from 1 to 1000.
When n is a prime number, the prime factorization is just n itself, written in bold below.
The number 1 is called a unit. It has no prime factors and is neither prime nor composite.
See also: Table of divisors (prime and non-prime divisors for 1 to 1000)
[edit] Properties
Many properties of a natural number n can be seen or directly computed from the prime factorization of n.
- The multiplicity of a prime factor p of n is the largest exponent m for which pm divides n. The tables show the multiplicity for each prime factor. If no exponent is written then the multiplicity is 1 (since p = p1). The multiplicity of a prime which does not divide n may be called 0 or may be considered undefined.
- Ω(n), the big Omega function, is the number of prime factors of n counted with multiplicity (so it is the sum of all prime factor multiplicities).
- A prime number has Ω(n) = 1. The first: 2, 3, 5, 7, 11 (sequence A000040 in OEIS). There are many special types of prime numbers.
- A composite number has Ω(n) > 1. The first: 4, 6, 8, 9, 10 (A002808). All numbers above 1 are either prime or composite. 1 is neither.
- A semiprime has Ω(n) = 2 (so it is composite). The first: 4, 6, 9, 10, 14 (A001358).
- A k-almost prime (for a natural number k) has Ω(n) = k (so it is composite if k > 1).
- An even number has the prime factor 2. The first: 2, 4, 6, 8, 10 (A005843).
- An odd number does not have the prime factor 2. The first: 1, 3, 5, 7, 9 (A005408). All integers are either even or odd.
- A square has even multiplicity for all prime factors (it is of the form a2 for some a). The first: 1, 4, 9, 16, 25 (A000290).
- A cube has all multiplicities divisible by 3 (it is of the form a3 for some a). The first: 1, 8, 27, 64, 125 (A000578).
- A perfect power has a common divisor m > 1 for all multiplicities (it is of the form am for some a > 1 and m > 1). The first: 4, 8, 9, 16, 25 (A001597). 1 is sometimes included.
- A powerful number (also called squareful) has multiplicity above 1 for all prime factors. The first: 1, 4, 8, 9, 16 (A001694).
- An Achilles number is powerful but not a perfect power. The first: 72, 108, 200, 288, 392 (A052486).
- A square-free integer has no prime factor with multiplicity above 1. The first: 1, 2, 3, 5, 6 (A005117). A number where some but not all prime factors have multiplicity above 1 is neither square-free nor squareful.
- The Liouville function λ(n) is 1 if Ω(n) is even, and is -1 if Ω(n) is odd.
- The Möbius function μ(n) is 0 if n is not square-free. Otherwise μ(n) is 1 if Ω(n) is even, and is −1 if Ω(n) is odd.
- A sphenic number has Ω(n) = 3 and is square-free (so it is the product of 3 distinct primes). The first: 30, 42, 66, 70, 78 (A007304).
- a0(n) is the sum of primes dividing n, counted with multiplicity. It is an additive function.
- A Ruth-Aaron pair is two consecutive numbers (x, x+1) with a0(x) = a0(x+1). The first: (5, 6), (8, 9), (15, 16), (77, 78), (125, 126) (x is in A039752).
- A primorial x# is the product of all primes from 2 to x. The first: 2, 6, 30, 210, 2310 (A002110). 1# = 1 is sometimes included.
- A factorial x! is the product of all numbers from 1 to x. The first: 1, 2, 6, 24, 120 (A000142).
- A k-smooth number (for a natural number k) has largest prime factor ≤ k (so it is also j-smooth for any j > k).
- m is smoother than n if the largest prime factor of m is below the largest of n.
- A regular number has no prime factor above 5 (so it is 5-smooth). The first: 1, 2, 3, 4, 5, 6, 8 (A051037).
- A k-powersmooth number has all pm ≤ k where p is a prime factor with multiplicity m.
- A frugal number has more digits than the number of digits in its prime factorization (when written like below tables with multiplicities above 1 as exponents). The first in decimal: 125, 128, 243, 256, 343 (A046759).
- An equidigital number has the same number of digits as its prime factorization. The first in decimal: 1, 2, 3, 5, 7, 10 (A046758).
- An extravagant number has fewer digits than its prime factorization. The first in decimal: 4, 6, 8, 9, 12 (A046760).
- An economical number has been defined as a frugal number, but also as a number that is either frugal or equidigital.
- gcd(m, n) (greatest common divisor of m and n) is the product of all prime factors which are both in m and n (with the smallest multiplicity for m and n).
- m and n are coprime (also called relatively prime) if gcd(m, n) = 1 (meaning they have no common prime factor).
- lcm(m, n) (least common multiple of m and n) is the product of all prime factors of m or n (with the largest multiplicity for m or n).
- gcd(m, n) × lcm(m, n) = m × n. Finding the prime factors is often harder than to compute gcd and lcm with other algorithms which do not require known prime factorization.
- m is a divisor of n (also called m divides n, or n is divisible by m) if all prime factors of m have at least the same multiplicity in n.
The divisors of n are all products of some or all prime factors of n (including the empty product 1 of no prime factors). The number of divisors can be computed by increasing all multiplicities by 1 and then multiplying them. Divisors and properties related to divisors are shown in table of divisors.
[edit] 1 to 100
If numbers are arranged in increasing columns of n numbers, then the prime factors of n will occur in the same row each time. The table columns have 20 = 22·5 numbers, so the prime factors 2 and 5 occur in fixed rows.
[edit] 101 to 200
[edit] 201 to 300
[edit] 301 to 400
[edit] 401 to 500
[edit] 501 to 600
[edit] 601 to 700
[edit] 701 to 800
|
|
|
|
761 − 780
| 761 |
761 |
| 762 |
2·3·127 |
| 763 |
7·109 |
| 764 |
22·191 |
| 765 |
32·5·17 |
| 766 |
2·383 |
| 767 |
13·59 |
| 768 |
28·3 |
| 769 |
769 |
| 770 |
2·5·7·11 |
| 771 |
3·257 |
| 772 |
22·193 |
| 773 |
773 |
| 774 |
2·32·43 |
| 775 |
52·31 |
| 776 |
23·97 |
| 777 |
3·7·37 |
| 778 |
2·389 |
| 779 |
19·41 |
| 780 |
22·3·5·13 |
|
781 − 800
| 781 |
11·71 |
| 782 |
2·17·23 |
| 783 |
33·29 |
| 784 |
24·72 |
| 785 |
5·157 |
| 786 |
2·3·131 |
| 787 |
787 |
| 788 |
22·197 |
| 789 |
3·263 |
| 790 |
2·5·79 |
| 791 |
7·113 |
| 792 |
23·32·11 |
| 793 |
13·61 |
| 794 |
2·397 |
| 795 |
3·5·53 |
| 796 |
22·199 |
| 797 |
797 |
| 798 |
2·3·7·19 |
| 799 |
17·47 |
| 800 |
25·52 |
|
[edit] 801 to 900
801 − 820
| 801 |
32·89 |
| 802 |
2·401 |
| 803 |
11·73 |
| 804 |
22·3·67 |
| 805 |
5·7·23 |
| 806 |
2·13·31 |
| 807 |
3·269 |
| 808 |
23·101 |
| 809 |
809 |
| 810 |
2·34·5 |
| 811 |
811 |
| 812 |
22·7·29 |
| 813 |
3·271 |
| 814 |
2·11·37 |
| 815 |
5·163 |
| 816 |
24·3·17 |
| 817 |
19·43 |
| 818 |
2·409 |
| 819 |
32·7·13 |
| 820 |
22·5·41 |
|
821 − 840
| 821 |
821 |
| 822 |
2·3·137 |
| 823 |
823 |
| 824 |
23·103 |
| 825 |
3·52·11 |
| 826 |
2·7·59 |
| 827 |
827 |
| 828 |
22·32·23 |
| 829 |
829 |
| 830 |
2·5·83 |
| 831 |
3·277 |
| 832 |
26·13 |
| 833 |
72·17 |
| 834 |
2·3·139 |
| 835 |
5·167 |
| 836 |
22·11·19 |
| 837 |
33·31 |
| 838 |
2·419 |
| 839 |
839 |
| 840 |
23·3·5·7 |
|
841 − 860
| 841 |
292 |
| 842 |
2·421 |
| 843 |
3·281 |
| 844 |
22·211 |
| 845 |
5·132 |
| 846 |
2·32·47 |
| 847 |
7·112 |
| 848 |
24·53 |
| 849 |
3·283 |
| 850 |
2·52·17 |
| 851 |
23·37 |
| 852 |
22·3·71 |
| 853 |
853 |
| 854 |
2·7·61 |
| 855 |
32·5·19 |
| 856 |
23·107 |
| 857 |
857 |
| 858 |
2·3·11·13 |
| 859 |
859 |
| 860 |
22·5·43 |
|
861 − 880
| 861 |
3·7·41 |
| 862 |
2·431 |
| 863 |
863 |
| 864 |
25·33 |
| 865 |
5·173 |
| 866 |
2·433 |
| 867 |
3·172 |
| 868 |
22·7·31 |
| 869 |
11·79 |
| 870 |
2·3·5·29 |
| 871 |
13·67 |
| 872 |
23·109 |
| 873 |
32·97 |
| 874 |
2·19·23 |
| 875 |
53·7 |
| 876 |
22·3·73 |
| 877 |
877 |
| 878 |
2·439 |
| 879 |
3·293 |
| 880 |
24·5·11 |
|
881 − 900
| 881 |
881 |
| 882 |
2·32·72 |
| 883 |
883 |
| 884 |
22·13·17 |
| 885 |
3·5·59 |
| 886 |
2·443 |
| 887 |
887 |
| 888 |
23·3·37 |
| 889 |
7·127 |
| 890 |
2·5·89 |
| 891 |
34·11 |
| 892 |
22·223 |
| 893 |
19·47 |
| 894 |
2·3·149 |
| 895 |
5·179 |
| 896 |
27·7 |
| 897 |
3·13·23 |
| 898 |
2·449 |
| 899 |
29·31 |
| 900 |
22·32·52 |
|
[edit] 901 to 1000
901 − 920
| 901 |
17·53 |
| 902 |
2·11·41 |
| 903 |
3·7·43 |
| 904 |
23·113 |
| 905 |
5·181 |
| 906 |
2·3·151 |
| 907 |
907 |
| 908 |
22·227 |
| 909 |
32·101 |
| 910 |
2·5·7·13 |
| 911 |
911 |
| 912 |
24·3·19 |
| 913 |
11·83 |
| 914 |
2·457 |
| 915 |
3·5·61 |
| 916 |
22·229 |
| 917 |
7·131 |
| 918 |
2·33·17 |
| 919 |
919 |
| 920 |
23·5·23 |
|
921 − 940
| 921 |
3·307 |
| 922 |
2·461 |
| 923 |
13·71 |
| 924 |
22·3·7·11 |
| 925 |
52·37 |
| 926 |
2·463 |
| 927 |
32·103 |
| 928 |
25·29 |
| 929 |
929 |
| 930 |
2·3·5·31 |
| 931 |
72·19 |
| 932 |
22·233 |
| 933 |
3·311 |
| 934 |
2·467 |
| 935 |
5·11·17 |
| 936 |
23·32·13 |
| 937 |
937 |
| 938 |
2·7·67 |
| 939 |
3·313 |
| 940 |
22·5·47 |
|
941 − 960
| 941 |
941 |
| 942 |
2·3·157 |
| 943 |
23·41 |
| 944 |
24·59 |
| 945 |
33·5·7 |
| 946 |
2·11·43 |
| 947 |
947 |
| 948 |
22·3·79 |
| 949 |
13·73 |
| 950 |
2·52·19 |
| 951 |
3·317 |
| 952 |
23·7·17 |
| 953 |
953 |
| 954 |
2·32·53 |
| 955 |
5·191 |
| 956 |
22·239 |
| 957 |
3·11·29 |
| 958 |
2·479 |
| 959 |
7·137 |
| 960 |
26·3·5 |
|
961 − 980
| 961 |
312 |
| 962 |
2·13·37 |
| 963 |
32·107 |
| 964 |
22·241 |
| 965 |
5·193 |
| 966 |
2·3·7·23 |
| 967 |
967 |
| 968 |
23·112 |
| 969 |
3·17·19 |
| 970 |
2·5·97 |
| 971 |
971 |
| 972 |
22·35 |
| 973 |
7·139 |
| 974 |
2·487 |
| 975 |
3·52·13 |
| 976 |
24·61 |
| 977 |
977 |
| 978 |
2·3·163 |
| 979 |
11·89 |
| 980 |
22·5·72 |
|
981 − 1000
| 981 |
32·109 |
| 982 |
2·491 |
| 983 |
983 |
| 984 |
23·3·41 |
| 985 |
5·197 |
| 986 |
2·17·29 |
| 987 |
3·7·47 |
| 988 |
22·13·19 |
| 989 |
23·43 |
| 990 |
2·32·5·11 |
| 991 |
991 |
| 992 |
25·31 |
| 993 |
3·331 |
| 994 |
2·7·71 |
| 995 |
5·199 |
| 996 |
22·3·83 |
| 997 |
997 |
| 998 |
2·499 |
| 999 |
33·37 |
| 1000 |
23·53 |
|