21638013976 has 32 divisors (see below), whose sum is σ = 40998999600. Its totient is φ = 10705530240.

The previous prime is 21638013953. The next prime is 21638014003. The reversal of 21638013976 is 67931083612.

It is a congruent 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, 262386 + ... + 334846.

Almost surely, 2^21638013976 is an apocalyptic number.

It is an amenable number.

21638013976 is a deficient number, since it is larger than the sum of its proper divisors (19360985624).

21638013976 is a wasteful number, since it uses less digits than its factorization.

21638013976 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 72859 (or 72855 counting only the distinct ones).

The product of its (nonzero) digits is 326592, while the sum is 46.

The spelling of 21638013976 in words is "twenty-one billion, six hundred thirty-eight million, thirteen thousand, nine hundred seventy-six".