668567839 has 4 divisors (see below), whose sum is σ = 703755640. Its totient is φ = 633380040.

The previous prime is 668567821. The next prime is 668567849. The reversal of 668567839 is 938765866.

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 668567839 - 2⁵ = 668567807 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (668567849) 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 3 ways as a sum of consecutive naturals, for example, 17593872 + ... + 17593909.

It is an arithmetic number, because the mean of its divisors is an integer number (175938910).

Almost surely, 2^668567839 is an apocalyptic number.

668567839 is a deficient number, since it is larger than the sum of its proper divisors (35187801).

668567839 is a wasteful number, since it uses less digits than its factorization.

668567839 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 35187800.

The product of its digits is 13063680, while the sum is 58.

The square root of 668567839 is about 25856.6788083853. The cubic root of 668567839 is about 874.4100901102.

The spelling of 668567839 in words is "six hundred sixty-eight million, five hundred sixty-seven thousand, eight hundred thirty-nine".