21638730026 has 16 divisors (see below), whose sum is σ = 32651527680. Its totient is φ = 10755078960.

The previous prime is 21638729989. The next prime is 21638730049. The reversal of 21638730026 is 62003783612.

It is a super-3 number, since 3×21638730026³ (a number of 32 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

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, 180071 + ... + 275141.

It is an arithmetic number, because the mean of its divisors is an integer number (2040720480).

Almost surely, 2^21638730026 is an apocalyptic number.

21638730026 is a deficient number, since it is larger than the sum of its proper divisors (11012797654).

21638730026 is a wasteful number, since it uses less digits than its factorization.

21638730026 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 95749.

The product of its (nonzero) digits is 72576, while the sum is 38.

The spelling of 21638730026 in words is "twenty-one billion, six hundred thirty-eight million, seven hundred thirty thousand, twenty-six".