20687620864 has 36 divisors (see below), whose sum is σ = 41695400656. Its totient is φ = 10243372032.

The previous prime is 20687620787. The next prime is 20687620903. The reversal of 20687620864 is 46802678602.

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, 365919 + ... + 418654.

Almost surely, 2^20687620864 is an apocalyptic number.

It is an amenable number.

20687620864 is an abundant number, since it is smaller than the sum of its proper divisors (21007779792).

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

20687620864 is an equidigital number, since it uses as much as digits as its factorization.

20687620864 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 784692 (or 784678 counting only the distinct ones).

The product of its (nonzero) digits is 1548288, while the sum is 49.

The spelling of 20687620864 in words is "twenty billion, six hundred eighty-seven million, six hundred twenty thousand, eight hundred sixty-four".