20931264 has 56 divisors (see below), whose sum is σ = 61539120. Its totient is φ = 6976512.

The previous prime is 20931263. The next prime is 20931289. The reversal of 20931264 is 46213902.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is not an unprimeable number, because it can be changed into a prime (20931263) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4329 + ... + 7784.

Almost surely, 2^20931264 is an apocalyptic number.

20931264 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

20931264 is an abundant number, since it is smaller than the sum of its proper divisors (40607856).

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

20931264 is a wasteful number, since it uses less digits than its factorization.

20931264 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12134 (or 12118 counting only the distinct ones).

The product of its (nonzero) digits is 2592, while the sum is 27.

The square root of 20931264 is about 4575.0698355326. The cubic root of 20931264 is about 275.5910768561.

The spelling of 20931264 in words is "twenty million, nine hundred thirty-one thousand, two hundred sixty-four".