20978307264 has 28 divisors (see below), whose sum is σ = 55505105144. Its totient is φ = 6992769024.

The previous prime is 20978307253. The next prime is 20978307277. The reversal of 20978307264 is 46270387902.

It is a Harshad number since it is a multiple of its sum of digits (48).

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, 54630817 + ... + 54631200.

Almost surely, 2^20978307264 is an apocalyptic number.

20978307264 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

20978307264 is an abundant number, since it is smaller than the sum of its proper divisors (34526797880).

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

20978307264 is a wasteful number, since it uses less digits than its factorization.

20978307264 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 109262032 (or 109262022 counting only the distinct ones).

The product of its (nonzero) digits is 1016064, while the sum is 48.

The spelling of 20978307264 in words is "twenty billion, nine hundred seventy-eight million, three hundred seven thousand, two hundred sixty-four".