Is 100 a prime number?

No, 100 is composite. It is divisible by 2, 4, 5, 10, 20, 25 and 50.

Factors of 100

The factors of 100 are 1, 2, 4, 5, 10, 20, 25, 50 and 100. That is 9 factors in total.

A factor of 100 is a whole number that divides 100 exactly, with no remainder. 100 is a composite number because it has factors other than 1 and itself.

Factor pairs of 100

Two numbers that multiply to give 100:

1 × 100 = 100
2 × 50 = 100
4 × 25 = 100
5 × 20 = 100
10 × 10 = 100

Prime factorization of 100

100 = 2 × 2 × 5 × 5 = 2² × 5². The prime factors of 100 are 2 and 5.

Quick facts about 100

Is 100 prime? No.
Even or odd: even.
Sum of its factors: 1 + 2 + 4 + 5 + 10 + 20 + 25 + 50 + 100 = 217.
100 is a perfect square (10 × 10), so it has an odd number of factors.

Factors of nearby numbers

Number	Factors
96	1, 2, 3, 4, 6, 8, 12, 16, 24, 32, 48, 96
97	1, 97
98	1, 2, 7, 14, 49, 98
99	1, 3, 9, 11, 33, 99
101	1, 101
102	1, 2, 3, 6, 17, 34, 51, 102
103	1, 103
104	1, 2, 4, 8, 13, 26, 52, 104

More about 100: 100 squared · square root of 100 · 100 in binary · 100 in Roman numerals.

Another number? Try the prime number checker, the GCF and LCM calculator or see all factor lists.