21007456164 has 24 divisors (see below), whose sum is σ = 54463775520. Its totient is φ = 7002485352.

The previous prime is 21007456159. The next prime is 21007456201. The reversal of 21007456164 is 46165470012.

21007456164 is a `hidden beast` number, since 21 + 0 + 0 + 74 + 561 + 6 + 4 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

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, 97256634 + ... + 97256849.

It is an arithmetic number, because the mean of its divisors is an integer number (2269323980).

Almost surely, 2^21007456164 is an apocalyptic number.

It is an amenable number.

21007456164 is an abundant number, since it is smaller than the sum of its proper divisors (33456319356).

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

21007456164 is a wasteful number, since it uses less digits than its factorization.

21007456164 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 194513496 (or 194513488 counting only the distinct ones).

The product of its (nonzero) digits is 40320, while the sum is 36.

The spelling of 21007456164 in words is "twenty-one billion, seven million, four hundred fifty-six thousand, one hundred sixty-four".