666560 has 28 divisors (see below), whose sum is σ = 1588008. Its totient is φ = 266496.

The previous prime is 666559. The next prime is 666599. The reversal of 666560 is 65666.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 722 + ... + 1361.

2⁶⁶⁶⁵⁶⁰ is an apocalyptic number.

It is an amenable number.

666560 is an abundant number, since it is smaller than the sum of its proper divisors (921448).

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

666560 is a wasteful number, since it uses less digits than its factorization.

666560 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2100 (or 2090 counting only the distinct ones).

The product of its (nonzero) digits is 6480, while the sum is 29.

The square root of 666560 is about 816.4312585883. The cubic root of 666560 is about 87.3533871293.

It can be divided in two parts, 6 and 66560, that added together give a palindrome (66566).

The spelling of 666560 in words is "six hundred sixty-six thousand, five hundred sixty".