20871264 has 24 divisors (see below), whose sum is σ = 54787320. Its totient is φ = 6957056.

The previous prime is 20871251. The next prime is 20871283. The reversal of 20871264 is 46217802.

It is a tau number, because it is divible by the number of its divisors (24).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 108609 + ... + 108800.

It is an arithmetic number, because the mean of its divisors is an integer number (2282805).

Almost surely, 2^20871264 is an apocalyptic number.

20871264 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

20871264 is an abundant number, since it is smaller than the sum of its proper divisors (33916056).

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

20871264 is a wasteful number, since it uses less digits than its factorization.

20871264 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 217422 (or 217414 counting only the distinct ones).

The product of its (nonzero) digits is 5376, while the sum is 30.

The square root of 20871264 is about 4568.5078526801. The cubic root of 20871264 is about 275.3274952333.

The spelling of 20871264 in words is "twenty million, eight hundred seventy-one thousand, two hundred sixty-four".