668767331 has 4 divisors (see below), whose sum is σ = 669580752. Its totient is φ = 667953912.

The previous prime is 668767291. The next prime is 668767367. The reversal of 668767331 is 133767866.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 668767331 - 2²⁶ = 601658467 is a prime.

It is a super-2 number, since 2×668767331² = 894499486025727122, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (668769331) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 405476 + ... + 407121.

It is an arithmetic number, because the mean of its divisors is an integer number (167395188).

Almost surely, 2^668767331 is an apocalyptic number.

668767331 is a deficient number, since it is larger than the sum of its proper divisors (813421).

668767331 is an equidigital number, since it uses as much as digits as its factorization.

668767331 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 813420.

The product of its digits is 762048, while the sum is 47.

The square root of 668767331 is about 25860.5361700024. The cubic root of 668767331 is about 874.4970523502.

The spelling of 668767331 in words is "six hundred sixty-eight million, seven hundred sixty-seven thousand, three hundred thirty-one".