668535617 has 2 divisors, whose sum is σ = 668535618. Its totient is φ = 668535616.

The previous prime is 668535601. The next prime is 668535629. The reversal of 668535617 is 716535866.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 668170801 + 364816 = 25849^2 + 604^2 .

It is a cyclic number.

It is not a de Polignac number, because 668535617 - 2⁴ = 668535601 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (668535697) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 334267808 + 334267809.

It is an arithmetic number, because the mean of its divisors is an integer number (334267809).

Almost surely, 2^668535617 is an apocalyptic number.

It is an amenable number.

668535617 is a deficient number, since it is larger than the sum of its proper divisors (1).

668535617 is an equidigital number, since it uses as much as digits as its factorization.

668535617 is an evil number, because the sum of its binary digits is even.

The product of its digits is 907200, while the sum is 47.

The square root of 668535617 is about 25856.0557123472. The cubic root of 668535617 is about 874.3960423238.

The spelling of 668535617 in words is "six hundred sixty-eight million, five hundred thirty-five thousand, six hundred seventeen".