668407817 has 16 divisors (see below), whose sum is σ = 838173312. Its totient is φ = 517816320.

The previous prime is 668407813. The next prime is 668407837. The reversal of 668407817 is 718704866.

It is not a de Polignac number, because 668407817 - 2² = 668407813 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (668407813) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 11768 + ... + 38409.

It is an arithmetic number, because the mean of its divisors is an integer number (52385832).

Almost surely, 2^668407817 is an apocalyptic number.

It is an amenable number.

668407817 is a deficient number, since it is larger than the sum of its proper divisors (169765495).

668407817 is a wasteful number, since it uses less digits than its factorization.

668407817 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 50368.

The product of its (nonzero) digits is 451584, while the sum is 47.

The square root of 668407817 is about 25853.5842196010. The cubic root of 668407817 is about 874.3403210664.

The spelling of 668407817 in words is "six hundred sixty-eight million, four hundred seven thousand, eight hundred seventeen".