664684 has 12 divisors (see below), whose sum is σ = 1174824. Its totient is φ = 329024.

The previous prime is 664679. The next prime is 664687. The reversal of 664684 is 486466.

It is an Ulam number.

It is not an unprimeable number, because it can be changed into a prime (664687) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 349 + ... + 1204.

It is an arithmetic number, because the mean of its divisors is an integer number (97902).

2⁶⁶⁴⁶⁸⁴ is an apocalyptic number.

It is an amenable number.

664684 is a deficient number, since it is larger than the sum of its proper divisors (510140).

664684 is a wasteful number, since it uses less digits than its factorization.

664684 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1664 (or 1662 counting only the distinct ones).

The product of its digits is 27648, while the sum is 34.

The square root of 664684 is about 815.2815464611. The cubic root of 664684 is about 87.2713595377.

The spelling of 664684 in words is "six hundred sixty-four thousand, six hundred eighty-four".