20516521264 has 20 divisors (see below), whose sum is σ = 42089040504. Its totient is φ = 9654833408.

The previous prime is 20516521253. The next prime is 20516521273. The reversal of 20516521264 is 46212561502.

It is a Harshad number since it is a multiple of its sum of digits (34).

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, 37713922 + ... + 37714465.

Almost surely, 2^20516521264 is an apocalyptic number.

It is an amenable number.

20516521264 is an abundant number, since it is smaller than the sum of its proper divisors (21572519240).

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

20516521264 is a wasteful number, since it uses less digits than its factorization.

20516521264 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 75428412 (or 75428406 counting only the distinct ones).

The product of its (nonzero) digits is 28800, while the sum is 34.

The spelling of 20516521264 in words is "twenty billion, five hundred sixteen million, five hundred twenty-one thousand, two hundred sixty-four".