668678715 has 24 divisors (see below), whose sum is σ = 1170999648. Its totient is φ = 352949760.

The previous prime is 668678713. The next prime is 668678737. The reversal of 668678715 is 517876866.

It is not a de Polignac number, because 668678715 - 2¹ = 668678713 is a prime.

It is not an unprimeable number, because it can be changed into a prime (668678713) 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 in 23 ways as a sum of consecutive naturals, for example, 72231 + ... + 80960.

It is an arithmetic number, because the mean of its divisors is an integer number (48791652).

Almost surely, 2^668678715 is an apocalyptic number.

668678715 is a deficient number, since it is larger than the sum of its proper divisors (502320933).

668678715 is a wasteful number, since it uses less digits than its factorization.

668678715 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 153299 (or 153296 counting only the distinct ones).

The product of its digits is 3386880, while the sum is 54.

The square root of 668678715 is about 25858.8227690280. The cubic root of 668678715 is about 874.4584251375.

The spelling of 668678715 in words is "six hundred sixty-eight million, six hundred seventy-eight thousand, seven hundred fifteen".