21164555064 has 32 divisors (see below), whose sum is σ = 52915029120. Its totient is φ = 7054366176.

The previous prime is 21164555057. The next prime is 21164555089. The reversal of 21164555064 is 46055546112.

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, 560179 + ... + 596765.

It is an arithmetic number, because the mean of its divisors is an integer number (1653594660).

Almost surely, 2^21164555064 is an apocalyptic number.

21164555064 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

21164555064 is an abundant number, since it is smaller than the sum of its proper divisors (31750474056).

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

21164555064 is a wasteful number, since it uses less digits than its factorization.

21164555064 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 60699 (or 60695 counting only the distinct ones).

The product of its (nonzero) digits is 144000, while the sum is 39.

The spelling of 21164555064 in words is "twenty-one billion, one hundred sixty-four million, five hundred fifty-five thousand, sixty-four".