666604 has 12 divisors (see below), whose sum is σ = 1235304. Its totient is φ = 313664.

The previous prime is 666599. The next prime is 666607. The reversal of 666604 is 406666.

It is a nialpdrome in base 7.

It is not an unprimeable number, because it can be changed into a prime (666607) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4834 + ... + 4969.

It is an arithmetic number, because the mean of its divisors is an integer number (102942).

2⁶⁶⁶⁶⁰⁴ is an apocalyptic number.

It is an amenable number.

666604 is a deficient number, since it is larger than the sum of its proper divisors (568700).

666604 is a wasteful number, since it uses less digits than its factorization.

666604 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9824 (or 9822 counting only the distinct ones).

The product of its (nonzero) digits is 5184, while the sum is 28.

The square root of 666604 is about 816.4582046866. The cubic root of 666604 is about 87.3553091691.

It can be divided in two parts, 66 and 6604, that added together give a triangular number (6670 = T₁₁₅).

The spelling of 666604 in words is "six hundred sixty-six thousand, six hundred four".