521166972168 has 24 divisors (see below), whose sum is σ = 1411493883150. Its totient is φ = 173722324032.

The previous prime is 521166972163. The next prime is 521166972211. The reversal of 521166972168 is 861279661125.

It is a happy number.

521166972168 is a `hidden beast` number, since 521 + 1 + 6 + 6 + 97 + 21 + 6 + 8 = 666.

It can be written as a sum of positive squares in only one way, i.e., 306873897444 + 214293074724 = 553962^2 + 462918^2 .

It is a tau number, because it is divible by the number of its divisors (24).

It is not an unprimeable number, because it can be changed into a prime (521166972163) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 3619215013 + ... + 3619215156.

Almost surely, 2^521166972168 is an apocalyptic number.

It is an amenable number.

521166972168 is an abundant number, since it is smaller than the sum of its proper divisors (890326910982).

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

521166972168 is a wasteful number, since it uses less digits than its factorization.

521166972168 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7238430181 (or 7238430174 counting only the distinct ones).

The product of its digits is 2177280, while the sum is 54.

The spelling of 521166972168 in words is "five hundred twenty-one billion, one hundred sixty-six million, nine hundred seventy-two thousand, one hundred sixty-eight".