20815688580 has 48 divisors (see below), whose sum is σ = 58818661440. Its totient is φ = 5499923328.

The previous prime is 20815688563. The next prime is 20815688581. The reversal of 20815688580 is 8588651802.

It is a hoax number, since the sum of its digits (51) coincides with the sum of the digits of its distinct prime factors.

It is not an unprimeable number, because it can be changed into a prime (20815688581) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1584874 + ... + 1597953.

It is an arithmetic number, because the mean of its divisors is an integer number (1225388780).

Almost surely, 2^20815688580 is an apocalyptic number.

20815688580 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20815688580 is an abundant number, since it is smaller than the sum of its proper divisors (38002972860).

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

20815688580 is a wasteful number, since it uses less digits than its factorization.

20815688580 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3182948 (or 3182946 counting only the distinct ones).

The product of its (nonzero) digits is 1228800, while the sum is 51.

The spelling of 20815688580 in words is "twenty billion, eight hundred fifteen million, six hundred eighty-eight thousand, five hundred eighty".