666536604 has 12 divisors (see below), whose sum is σ = 1555252104. Its totient is φ = 222178864.

The previous prime is 666536597. The next prime is 666536621. The reversal of 666536604 is 406635666.

It is a happy number.

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

It is a super-4 number, since 4×666536604⁴ (a number of 36 digits) contains 4444 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 27772347 + ... + 27772370.

It is an arithmetic number, because the mean of its divisors is an integer number (129604342).

Almost surely, 2^666536604 is an apocalyptic number.

It is an amenable number.

666536604 is an abundant number, since it is smaller than the sum of its proper divisors (888715500).

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

666536604 is a wasteful number, since it uses less digits than its factorization.

666536604 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 55544724 (or 55544722 counting only the distinct ones).

The product of its (nonzero) digits is 466560, while the sum is 42.

The square root of 666536604 is about 25817.3701991508. The cubic root of 666536604 is about 873.5236509391.

The spelling of 666536604 in words is "six hundred sixty-six million, five hundred thirty-six thousand, six hundred four".