21659676938 has 16 divisors (see below), whose sum is σ = 33373394664. Its totient is φ = 10535313600.

The previous prime is 21659676917. The next prime is 21659676959. The reversal of 21659676938 is 83967695612.

It is an interprime number because it is at equal distance from previous prime (21659676917) and next prime (21659676959).

It can be written as a sum of positive squares in 4 ways, for example, as 21402812209 + 256864729 = 146297^2 + 16027^2 .

It is a Curzon number.

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, 469088 + ... + 513188.

Almost surely, 2^21659676938 is an apocalyptic number.

21659676938 is a deficient number, since it is larger than the sum of its proper divisors (11713717726).

21659676938 is a wasteful number, since it uses less digits than its factorization.

21659676938 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 50777.

The product of its digits is 29393280, while the sum is 62.

The spelling of 21659676938 in words is "twenty-one billion, six hundred fifty-nine million, six hundred seventy-six thousand, nine hundred thirty-eight".