668497831 has 2 divisors, whose sum is σ = 668497832. Its totient is φ = 668497830.

The previous prime is 668497807. The next prime is 668497859. The reversal of 668497831 is 138794866.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 668497831 - 2⁵ = 668497799 is a prime.

It is a super-2 number, since 2×668497831² = 893778700103409122, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (668497331) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 334248915 + 334248916.

It is an arithmetic number, because the mean of its divisors is an integer number (334248916).

Almost surely, 2^668497831 is an apocalyptic number.

668497831 is a deficient number, since it is larger than the sum of its proper divisors (1).

668497831 is an equidigital number, since it uses as much as digits as its factorization.

668497831 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1741824, while the sum is 52.

The square root of 668497831 is about 25855.3250027920. The cubic root of 668497831 is about 874.3795682320.

The spelling of 668497831 in words is "six hundred sixty-eight million, four hundred ninety-seven thousand, eight hundred thirty-one".