668507923 has 2 divisors, whose sum is σ = 668507924. Its totient is φ = 668507922.

The previous prime is 668507869. The next prime is 668507927. The reversal of 668507923 is 329705866.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-668507923 is a prime.

It is a super-2 number, since 2×668507923² = 893805686227547858, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (668507927) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 334253961 + 334253962.

It is an arithmetic number, because the mean of its divisors is an integer number (334253962).

Almost surely, 2^668507923 is an apocalyptic number.

668507923 is a deficient number, since it is larger than the sum of its proper divisors (1).

668507923 is an equidigital number, since it uses as much as digits as its factorization.

668507923 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 544320, while the sum is 46.

The square root of 668507923 is about 25855.5201649474. The cubic root of 668507923 is about 874.3839682434.

The spelling of 668507923 in words is "six hundred sixty-eight million, five hundred seven thousand, nine hundred twenty-three".