668746931 has 8 divisors (see below), whose sum is σ = 696788400. Its totient is φ = 641037600.

The previous prime is 668746921. The next prime is 668746993. The reversal of 668746931 is 139647866.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-668746931 is a prime.

It is a super-2 number, since 2×668746931² = 894444915443837522, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 668746931.

It is not an unprimeable number, because it can be changed into a prime (668746921) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 78920 + ... + 86981.

It is an arithmetic number, because the mean of its divisors is an integer number (87098550).

Almost surely, 2^668746931 is an apocalyptic number.

668746931 is a deficient number, since it is larger than the sum of its proper divisors (28041469).

668746931 is a wasteful number, since it uses less digits than its factorization.

668746931 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 166069.

The product of its digits is 1306368, while the sum is 50.

The square root of 668746931 is about 25860.1417436177. The cubic root of 668746931 is about 874.4881604080.

The spelling of 668746931 in words is "six hundred sixty-eight million, seven hundred forty-six thousand, nine hundred thirty-one".