668697913 has 16 divisors (see below), whose sum is σ = 763100800. Its totient is φ = 580867200.

The previous prime is 668697899. The next prime is 668697919. The reversal of 668697913 is 319796866.

It is a cyclic number.

It is not a de Polignac number, because 668697913 - 2²¹ = 666600761 is a prime.

It is not an unprimeable number, because it can be changed into a prime (668697919) 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 in 15 ways as a sum of consecutive naturals, for example, 28333 + ... + 46261.

It is an arithmetic number, because the mean of its divisors is an integer number (47693800).

Almost surely, 2^668697913 is an apocalyptic number.

It is an amenable number.

668697913 is a deficient number, since it is larger than the sum of its proper divisors (94402887).

668697913 is a wasteful number, since it uses less digits than its factorization.

668697913 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18112.

The product of its digits is 2939328, while the sum is 55.

The square root of 668697913 is about 25859.1939742908. The cubic root of 668697913 is about 874.4667937265.

The spelling of 668697913 in words is "six hundred sixty-eight million, six hundred ninety-seven thousand, nine hundred thirteen".