660655578 has 16 divisors (see below), whose sum is σ = 1441430496. Its totient is φ = 200198640.

The previous prime is 660655561. The next prime is 660655603. The reversal of 660655578 is 875556066.

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5004901 + ... + 5005032.

It is an arithmetic number, because the mean of its divisors is an integer number (90089406).

Almost surely, 2^660655578 is an apocalyptic number.

660655578 is an abundant number, since it is smaller than the sum of its proper divisors (780774918).

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

660655578 is a wasteful number, since it uses less digits than its factorization.

660655578 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10009949.

The product of its (nonzero) digits is 1512000, while the sum is 48.

The square root of 660655578 is about 25703.2211600025. The cubic root of 660655578 is about 870.9469488406.

The spelling of 660655578 in words is "six hundred sixty million, six hundred fifty-five thousand, five hundred seventy-eight".