20157156 has 54 divisors (see below), whose sum is σ = 52495170. Its totient is φ = 6521472.

The previous prime is 20157149. The next prime is 20157169. The reversal of 20157156 is 65175102.

It can be written as a sum of positive squares in 3 ways, for example, as 15872256 + 4284900 = 3984^2 + 2070^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 49080 + ... + 49488.

Almost surely, 2^20157156 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20157156, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26247585).

20157156 is an abundant number, since it is smaller than the sum of its proper divisors (32338014).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

20157156 is a wasteful number, since it uses less digits than its factorization.

20157156 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 493 (or 451 counting only the distinct ones).

The product of its (nonzero) digits is 2100, while the sum is 27.

The square root of 20157156 is about 4489.6721483868. The cubic root of 20157156 is about 272.1508858630.

The spelling of 20157156 in words is "twenty million, one hundred fifty-seven thousand, one hundred fifty-six".