166316225621 has 32 divisors (see below), whose sum is σ = 218505369600. Its totient is φ = 122909088960.

The previous prime is 166316225617. The next prime is 166316225623. The reversal of 166316225621 is 126522613661.

It is a happy number.

It is not a de Polignac number, because 166316225621 - 2² = 166316225617 is a prime.

It is a super-2 number, since 2×166316225621² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (166316225623) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 554651 + ... + 800168.

It is an arithmetic number, because the mean of its divisors is an integer number (6828292800).

Almost surely, 2^166316225621 is an apocalyptic number.

It is an amenable number.

166316225621 is a deficient number, since it is larger than the sum of its proper divisors (52189143979).

166316225621 is a wasteful number, since it uses less digits than its factorization.

166316225621 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1354929.

The product of its digits is 155520, while the sum is 41.

The spelling of 166316225621 in words is "one hundred sixty-six billion, three hundred sixteen million, two hundred twenty-five thousand, six hundred twenty-one".