666564725 has 12 divisors (see below), whose sum is σ = 862477536. Its totient is φ = 510066480.

The previous prime is 666564719. The next prime is 666564749. The reversal of 666564725 is 527465666.

It is a happy number.

It is not a de Polignac number, because 666564725 - 2²² = 662370421 is a prime.

It is a super-2 number, since 2×666564725² = 888617065228651250, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 666564725.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 579047 + ... + 580196.

It is an arithmetic number, because the mean of its divisors is an integer number (71873128).

Almost surely, 2^666564725 is an apocalyptic number.

It is an amenable number.

666564725 is a deficient number, since it is larger than the sum of its proper divisors (195912811).

666564725 is a wasteful number, since it uses less digits than its factorization.

666564725 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1159276 (or 1159271 counting only the distinct ones).

The product of its digits is 1814400, while the sum is 47.

The square root of 666564725 is about 25817.9148073581. The cubic root of 666564725 is about 873.5359353423.

The spelling of 666564725 in words is "six hundred sixty-six million, five hundred sixty-four thousand, seven hundred twenty-five".