668319691 has 8 divisors (see below), whose sum is σ = 762066144. Its totient is φ = 580621440.

The previous prime is 668319689. The next prime is 668319709. The reversal of 668319691 is 196913866.

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

It is a cyclic number.

It is not a de Polignac number, because 668319691 - 2¹ = 668319689 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (668319611) 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, 1511815 + ... + 1512256.

It is an arithmetic number, because the mean of its divisors is an integer number (95258268).

Almost surely, 2^668319691 is an apocalyptic number.

668319691 is a deficient number, since it is larger than the sum of its proper divisors (93746453).

668319691 is a wasteful number, since it uses less digits than its factorization.

668319691 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3024101.

The product of its digits is 419904, while the sum is 49.

The square root of 668319691 is about 25851.8798349366. The cubic root of 668319691 is about 874.3018936773.

The spelling of 668319691 in words is "six hundred sixty-eight million, three hundred nineteen thousand, six hundred ninety-one".