660555 has 40 divisors (see below), whose sum is σ = 1359072. Its totient is φ = 300672.

The previous prime is 660547. The next prime is 660557. The reversal of 660555 is 555066.

660555 is a `hidden beast` number, since 6 + 605 + 55 = 666.

It is not a de Polignac number, because 660555 - 2³ = 660547 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is not an unprimeable number, because it can be changed into a prime (660557) by changing a digit.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 2719 + ... + 2951.

2⁶⁶⁰⁵⁵⁵ is an apocalyptic number.

660555 is an abundant number, since it is smaller than the sum of its proper divisors (698517).

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

660555 is a wasteful number, since it uses less digits than its factorization.

660555 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 257 (or 248 counting only the distinct ones).

The product of its (nonzero) digits is 4500, while the sum is 27.

The square root of 660555 is about 812.7453475720. The cubic root of 660555 is about 87.0902749033.

The spelling of 660555 in words is "six hundred sixty thousand, five hundred fifty-five".