668688953 has 2 divisors, whose sum is σ = 668688954. Its totient is φ = 668688952.

The previous prime is 668688929. The next prime is 668688961. The reversal of 668688953 is 359886866.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 620358649 + 48330304 = 24907^2 + 6952^2 .

It is a cyclic number.

It is not a de Polignac number, because 668688953 - 2²⁰ = 667640377 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 668688892 and 668688901.

It is not a weakly prime, because it can be changed into another prime (668618953) 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, 334344476 + 334344477.

It is an arithmetic number, because the mean of its divisors is an integer number (334344477).

Almost surely, 2^668688953 is an apocalyptic number.

It is an amenable number.

668688953 is a deficient number, since it is larger than the sum of its proper divisors (1).

668688953 is an equidigital number, since it uses as much as digits as its factorization.

668688953 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 14929920, while the sum is 59.

The square root of 668688953 is about 25859.0207277847. The cubic root of 668688953 is about 874.4628879981.

The spelling of 668688953 in words is "six hundred sixty-eight million, six hundred eighty-eight thousand, nine hundred fifty-three".