666604004 has 18 divisors (see below), whose sum is σ = 1282249542. Its totient is φ = 303001600.

The previous prime is 666603991. The next prime is 666604013. The reversal of 666604004 is 400406666.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 585640000 + 80964004 = 24200^2 + 8998^2 .

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 688157 + ... + 689124.

Almost surely, 2^666604004 is an apocalyptic number.

It is an amenable number.

666604004 is a deficient number, since it is larger than the sum of its proper divisors (615645538).

666604004 is a wasteful number, since it uses less digits than its factorization.

666604004 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1377307 (or 1377294 counting only the distinct ones).

The product of its (nonzero) digits is 20736, while the sum is 32.

The square root of 666604004 is about 25818.6754888782. The cubic root of 666604004 is about 873.5530934380.

The spelling of 666604004 in words is "six hundred sixty-six million, six hundred four thousand, four".