668698523 has 2 divisors, whose sum is σ = 668698524. Its totient is φ = 668698522.

The previous prime is 668698411. The next prime is 668698567. The reversal of 668698523 is 325896866.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 668698523 - 2⁸ = 668698267 is a prime.

It is not a weakly prime, because it can be changed into another prime (668692523) 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, 334349261 + 334349262.

It is an arithmetic number, because the mean of its divisors is an integer number (334349262).

Almost surely, 2^668698523 is an apocalyptic number.

668698523 is a deficient number, since it is larger than the sum of its proper divisors (1).

668698523 is an equidigital number, since it uses as much as digits as its factorization.

668698523 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 3732480, while the sum is 53.

The square root of 668698523 is about 25859.2057689327. The cubic root of 668698523 is about 874.4670596287.

The spelling of 668698523 in words is "six hundred sixty-eight million, six hundred ninety-eight thousand, five hundred twenty-three".