Prime Numbers up to 1,000
There are 168 prime numbers between 1 and 1,000.
What is a prime?
A prime number is a whole number greater than 1 whose only divisors are 1 and itself. 2 is the only even prime. 1 is not prime, because a prime must have exactly two divisors. Every whole number greater than 1 can be written as a product of primes in exactly one way — the fundamental theorem of arithmetic.
Primes by hundred
1–100 (25 primes)
2, 3, 5, 7, 11, 13, 17, 19, 23, 29, 31, 37, 41, 43, 47, 53, 59, 61, 67, 71, 73, 79, 83, 89, 97
101–200 (21 primes)
101, 103, 107, 109, 113, 127, 131, 137, 139, 149, 151, 157, 163, 167, 173, 179, 181, 191, 193, 197, 199
201–300 (16 primes)
211, 223, 227, 229, 233, 239, 241, 251, 257, 263, 269, 271, 277, 281, 283, 293
301–400 (16 primes)
307, 311, 313, 317, 331, 337, 347, 349, 353, 359, 367, 373, 379, 383, 389, 397
401–500 (17 primes)
401, 409, 419, 421, 431, 433, 439, 443, 449, 457, 461, 463, 467, 479, 487, 491, 499
501–600 (14 primes)
503, 509, 521, 523, 541, 547, 557, 563, 569, 571, 577, 587, 593, 599
601–700 (16 primes)
601, 607, 613, 617, 619, 631, 641, 643, 647, 653, 659, 661, 673, 677, 683, 691
701–800 (14 primes)
701, 709, 719, 727, 733, 739, 743, 751, 757, 761, 769, 773, 787, 797
801–900 (15 primes)
809, 811, 821, 823, 827, 829, 839, 853, 857, 859, 863, 877, 881, 883, 887
901–1000 (14 primes)
907, 911, 919, 929, 937, 941, 947, 953, 967, 971, 977, 983, 991, 997
Quick divisibility tests
- By 2: the last digit is even.
- By 3: the digit sum is divisible by 3.
- By 5: the last digit is 0 or 5.
- By 11: the alternating digit sum (e.g. 9 − 1 + 3 for 913) is divisible by 11.
- To test n for primality you only need to try primes up to √n.