21164065026 has 24 divisors (see below), whose sum is σ = 45834604560. Its totient is φ = 6512019696.

The previous prime is 21164064979. The next prime is 21164065057. The reversal of 21164065026 is 62056046112.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 10434916 + ... + 10436943.

It is an arithmetic number, because the mean of its divisors is an integer number (1909775190).

Almost surely, 2^21164065026 is an apocalyptic number.

21164065026 is a gapful number since it is divisible by the number (26) formed by its first and last digit.

21164065026 is an abundant number, since it is smaller than the sum of its proper divisors (24670539534).

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

21164065026 is a wasteful number, since it uses less digits than its factorization.

21164065026 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20871890 (or 20871877 counting only the distinct ones).

The product of its (nonzero) digits is 17280, while the sum is 33.

The spelling of 21164065026 in words is "twenty-one billion, one hundred sixty-four million, sixty-five thousand, twenty-six".