21637668108 has 24 divisors (see below), whose sum is σ = 57700448512. Its totient is φ = 6182190864.

The previous prime is 21637668097. The next prime is 21637668127. The reversal of 21637668108 is 80186673612.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 128795560 + ... + 128795727.

Almost surely, 2^21637668108 is an apocalyptic number.

21637668108 is a gapful number since it is divisible by the number (28) formed by its first and last digit.

It is an amenable number.

21637668108 is an abundant number, since it is smaller than the sum of its proper divisors (36062780404).

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

21637668108 is a wasteful number, since it uses less digits than its factorization.

21637668108 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 257591301 (or 257591299 counting only the distinct ones).

The product of its (nonzero) digits is 580608, while the sum is 48.

The spelling of 21637668108 in words is "twenty-one billion, six hundred thirty-seven million, six hundred sixty-eight thousand, one hundred eight".