20931136 has 28 divisors (see below), whose sum is σ = 41696640. Its totient is φ = 10424960.

The previous prime is 20931133. The next prime is 20931137. The reversal of 20931136 is 63113902.

It is a super-2 number, since 2×20931136² = 876224908500992, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 20931136.

It is not an unprimeable number, because it can be changed into a prime (20931133) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 22521 + ... + 23431.

Almost surely, 2^20931136 is an apocalyptic number.

It is an amenable number.

20931136 is a deficient number, since it is larger than the sum of its proper divisors (20765504).

20931136 is an equidigital number, since it uses as much as digits as its factorization.

20931136 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1282 (or 1272 counting only the distinct ones).

The product of its (nonzero) digits is 972, while the sum is 25.

The square root of 20931136 is about 4575.0558466537. The cubic root of 20931136 is about 275.5905150851.

The spelling of 20931136 in words is "twenty million, nine hundred thirty-one thousand, one hundred thirty-six".