668348491 has 2 divisors, whose sum is σ = 668348492. Its totient is φ = 668348490.

The previous prime is 668348479. The next prime is 668348509. The reversal of 668348491 is 194843866.

668348491 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 668348491 - 2⁷ = 668348363 is a prime.

It is not a weakly prime, because it can be changed into another prime (668348431) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 334174245 + 334174246.

It is an arithmetic number, because the mean of its divisors is an integer number (334174246).

Almost surely, 2^668348491 is an apocalyptic number.

668348491 is a deficient number, since it is larger than the sum of its proper divisors (1).

668348491 is an equidigital number, since it uses as much as digits as its factorization.

668348491 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 995328, while the sum is 49.

The square root of 668348491 is about 25852.4368483901. The cubic root of 668348491 is about 874.3144523042.

The spelling of 668348491 in words is "six hundred sixty-eight million, three hundred forty-eight thousand, four hundred ninety-one".