660642406 has 16 divisors (see below), whose sum is σ = 1053972864. Its totient is φ = 309492864.

The previous prime is 660642379. The next prime is 660642421. The reversal of 660642406 is 604246066.

It is a Harshad number since it is a multiple of its sum of digits (34).

It is a congruent 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, 35985 + ... + 51148.

It is an arithmetic number, because the mean of its divisors is an integer number (65873304).

Almost surely, 2^660642406 is an apocalyptic number.

660642406 is a deficient number, since it is larger than the sum of its proper divisors (393330458).

660642406 is a wasteful number, since it uses less digits than its factorization.

660642406 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 87375.

The product of its (nonzero) digits is 41472, while the sum is 34.

The square root of 660642406 is about 25702.9649262493. The cubic root of 660642406 is about 870.9411605550.

The spelling of 660642406 in words is "six hundred sixty million, six hundred forty-two thousand, four hundred six".