668607660 has 72 divisors (see below), whose sum is σ = 2317844256. Its totient is φ = 152824320.

The previous prime is 668607607. The next prime is 668607733. The reversal of 668607660 is 66706866.

It is a happy number.

668607660 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 264061 + ... + 266580.

Almost surely, 2^668607660 is an apocalyptic number.

668607660 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

668607660 is an abundant number, since it is smaller than the sum of its proper divisors (1649236596).

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

668607660 is a wasteful number, since it uses less digits than its factorization.

668607660 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 530663 (or 530658 counting only the distinct ones).

The product of its (nonzero) digits is 435456, while the sum is 45.

The square root of 668607660 is about 25857.4488300760. The cubic root of 668607660 is about 874.4274501999.

The spelling of 668607660 in words is "six hundred sixty-eight million, six hundred seven thousand, six hundred sixty".