668660 has 24 divisors (see below), whose sum is σ = 1428000. Its totient is φ = 262944.

The previous prime is 668623. The next prime is 668671. The reversal of 668660 is 66866.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

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 7 ways as a sum of consecutive naturals, for example, 1091 + ... + 1589.

It is an arithmetic number, because the mean of its divisors is an integer number (59500).

2⁶⁶⁸⁶⁶⁰ is an apocalyptic number.

It is an amenable number.

668660 is an abundant number, since it is smaller than the sum of its proper divisors (759340).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

668660 is a wasteful number, since it uses less digits than its factorization.

668660 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 575 (or 573 counting only the distinct ones).

The product of its (nonzero) digits is 10368, while the sum is 32.

The square root of 668660 is about 817.7163322326. The cubic root of 668660 is about 87.4450266938.

The spelling of 668660 in words is "six hundred sixty-eight thousand, six hundred sixty".