668920 has 32 divisors (see below), whose sum is σ = 1720800. Its totient is φ = 229248.

The previous prime is 668903. The next prime is 668929. The reversal of 668920 is 29866.

668920 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (668929) by changing a digit.

668920 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 915 + ... + 1474.

It is an arithmetic number, because the mean of its divisors is an integer number (53775).

2⁶⁶⁸⁹²⁰ is an apocalyptic number.

It is an amenable number.

668920 is an abundant number, since it is smaller than the sum of its proper divisors (1051880).

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

668920 is a wasteful number, since it uses less digits than its factorization.

668920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2407 (or 2403 counting only the distinct ones).

The product of its (nonzero) digits is 5184, while the sum is 31.

The square root of 668920 is about 817.8752961179. The cubic root of 668920 is about 87.4563591901.

The spelling of 668920 in words is "six hundred sixty-eight thousand, nine hundred twenty".