668862720 has 108 divisors (see below), whose sum is σ = 2314235196. Its totient is φ = 178360320.

The previous prime is 668862713. The next prime is 668862731. The reversal of 668862720 is 27268866.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 189778176 + 479084544 = 13776^2 + 21888^2 .

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 11 ways as a sum of consecutive naturals, for example, 17511 + ... + 40550.

Almost surely, 2^668862720 is an apocalyptic number.

668862720 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

668862720 is an abundant number, since it is smaller than the sum of its proper divisors (1645372476).

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

668862720 is a wasteful number, since it uses less digits than its factorization.

668862720 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 58088 (or 58071 counting only the distinct ones).

The product of its (nonzero) digits is 387072, while the sum is 45.

The square root of 668862720 is about 25862.3804008834. The cubic root of 668862720 is about 874.5386280621.

The spelling of 668862720 in words is "six hundred sixty-eight million, eight hundred sixty-two thousand, seven hundred twenty".