668919737 has 2 divisors, whose sum is σ = 668919738. Its totient is φ = 668919736.

The previous prime is 668919721. The next prime is 668919773. The reversal of 668919737 is 737919866.

Together with next prime (668919773) it forms an Ormiston pair, because they use the same digits, order apart.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 584720761 + 84198976 = 24181^2 + 9176^2 .

It is a cyclic number.

It is not a de Polignac number, because 668919737 - 2⁴ = 668919721 is a prime.

It is a super-2 number, since 2×668919737² = 894907229096298338, which contains 22 as substring.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (668919037) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 334459868 + 334459869.

It is an arithmetic number, because the mean of its divisors is an integer number (334459869).

Almost surely, 2^668919737 is an apocalyptic number.

It is an amenable number.

668919737 is a deficient number, since it is larger than the sum of its proper divisors (1).

668919737 is an equidigital number, since it uses as much as digits as its factorization.

668919737 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 3429216, while the sum is 56.

The square root of 668919737 is about 25863.4826927852. The cubic root of 668919737 is about 874.5634772828.

The spelling of 668919737 in words is "six hundred sixty-eight million, nine hundred nineteen thousand, seven hundred thirty-seven".