660904 has 8 divisors (see below), whose sum is σ = 1239210. Its totient is φ = 330448.

The previous prime is 660901. The next prime is 660917. The reversal of 660904 is 409066.

It can be written as a sum of positive squares in only one way, i.e., 492804 + 168100 = 702^2 + 410^2 .

It is a tau number, because it is divible by the number of its divisors (8).

It is an Ulam number.

It is not an unprimeable number, because it can be changed into a prime (660901) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 41299 + ... + 41314.

2⁶⁶⁰⁹⁰⁴ is an apocalyptic number.

It is an amenable number.

660904 is a deficient number, since it is larger than the sum of its proper divisors (578306).

660904 is a wasteful number, since it uses less digits than its factorization.

660904 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 82619 (or 82615 counting only the distinct ones).

The product of its (nonzero) digits is 1296, while the sum is 25.

The square root of 660904 is about 812.9600236174. The cubic root of 660904 is about 87.1056100657.

The spelling of 660904 in words is "six hundred sixty thousand, nine hundred four".