668999744 has 42 divisors (see below), whose sum is σ = 1544295870. Its totient is φ = 286712832.

The previous prime is 668999743. The next prime is 668999767. The reversal of 668999744 is 447999866.

It can be written as a sum of positive squares in only one way, i.e., 640697344 + 28302400 = 25312^2 + 5320^2 .

It is not an unprimeable number, because it can be changed into a prime (668999741) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 103529 + ... + 109800.

Almost surely, 2^668999744 is an apocalyptic number.

668999744 is a gapful number since it is divisible by the number (64) formed by its first and last digit.

It is an amenable number.

668999744 is an abundant number, since it is smaller than the sum of its proper divisors (875296126).

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

668999744 is a wasteful number, since it uses less digits than its factorization.

668999744 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 213355 (or 213338 counting only the distinct ones).

The product of its digits is 23514624, while the sum is 62.

The square root of 668999744 is about 25865.0293639887. The cubic root of 668999744 is about 874.5983436536.

The spelling of 668999744 in words is "six hundred sixty-eight million, nine hundred ninety-nine thousand, seven hundred forty-four".