21079437864 has 16 divisors (see below), whose sum is σ = 52698594720. Its totient is φ = 7026479280.

The previous prime is 21079437853. The next prime is 21079437947. The reversal of 21079437864 is 46873497012.

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 an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 439154932 + ... + 439154979.

It is an arithmetic number, because the mean of its divisors is an integer number (3293662170).

Almost surely, 2^21079437864 is an apocalyptic number.

21079437864 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

21079437864 is an abundant number, since it is smaller than the sum of its proper divisors (31619156856).

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

21079437864 is a wasteful number, since it uses less digits than its factorization.

21079437864 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 878309920 (or 878309916 counting only the distinct ones).

The product of its (nonzero) digits is 2032128, while the sum is 51.

The spelling of 21079437864 in words is "twenty-one billion, seventy-nine million, four hundred thirty-seven thousand, eight hundred sixty-four".