660864 has 32 divisors (see below), whose sum is σ = 1756440. Its totient is φ = 220160.

The previous prime is 660853. The next prime is 660887. The reversal of 660864 is 468066.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (32).

It is a congruent number.

It is an unprimeable number.

660864 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 3 ways as a sum of consecutive naturals, for example, 477 + ... + 1244.

2⁶⁶⁰⁸⁶⁴ is an apocalyptic number.

660864 is a gapful number since it is divisible by the number (64) formed by its first and last digit.

It is an amenable number.

660864 is an abundant number, since it is smaller than the sum of its proper divisors (1095576).

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

660864 is a wasteful number, since it uses less digits than its factorization.

660864 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1738 (or 1726 counting only the distinct ones).

The product of its (nonzero) digits is 6912, while the sum is 30.

The square root of 660864 is about 812.9354217895. The cubic root of 660864 is about 87.1038527279.

The spelling of 660864 in words is "six hundred sixty thousand, eight hundred sixty-four".