664168557 has 16 divisors (see below), whose sum is σ = 954955008. Its totient is φ = 408171840.

The previous prime is 664168513. The next prime is 664168567. The reversal of 664168557 is 755861466.

It is not a de Polignac number, because 664168557 - 2⁷ = 664168429 is a prime.

It is a super-2 number, since 2×664168557² = 882239744214924498, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (664168507) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 19132 + ... + 41162.

It is an arithmetic number, because the mean of its divisors is an integer number (59684688).

Almost surely, 2^664168557 is an apocalyptic number.

It is an amenable number.

664168557 is a deficient number, since it is larger than the sum of its proper divisors (290786451).

664168557 is a wasteful number, since it uses less digits than its factorization.

664168557 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22820.

The product of its digits is 1209600, while the sum is 48.

The square root of 664168557 is about 25771.4678860169. The cubic root of 664168557 is about 872.4879490841.

The spelling of 664168557 in words is "six hundred sixty-four million, one hundred sixty-eight thousand, five hundred fifty-seven".