20664768972 has 12 divisors (see below), whose sum is σ = 48217794296. Its totient is φ = 6888256320.

The previous prime is 20664768941. The next prime is 20664768977. The reversal of 20664768972 is 27986746602.

It is a tau number, because it is divible by the number of its divisors (12).

It is a super-2 number, since 2×20664768972² (a number of 21 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (20664768977) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 861032029 + ... + 861032052.

Almost surely, 2^20664768972 is an apocalyptic number.

It is an amenable number.

20664768972 is an abundant number, since it is smaller than the sum of its proper divisors (27553025324).

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

20664768972 is a wasteful number, since it uses less digits than its factorization.

20664768972 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1722064088 (or 1722064086 counting only the distinct ones).

The product of its (nonzero) digits is 12192768, while the sum is 57.

The spelling of 20664768972 in words is "twenty billion, six hundred sixty-four million, seven hundred sixty-eight thousand, nine hundred seventy-two".