663604 has 6 divisors (see below), whose sum is σ = 1161314. Its totient is φ = 331800.

The previous prime is 663601. The next prime is 663631. The reversal of 663604 is 406366.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 487204 + 176400 = 698^2 + 420^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (663601) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 82947 + ... + 82954.

2⁶⁶³⁶⁰⁴ is an apocalyptic number.

It is an amenable number.

663604 is a deficient number, since it is larger than the sum of its proper divisors (497710).

663604 is a wasteful number, since it uses less digits than its factorization.

663604 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 165905 (or 165903 counting only the distinct ones).

The product of its (nonzero) digits is 2592, while the sum is 25.

The square root of 663604 is about 814.6189293160. The cubic root of 663604 is about 87.2240668077.

The spelling of 663604 in words is "six hundred sixty-three thousand, six hundred four".