668038611617 has 12 divisors (see below), whose sum is σ = 723410885484. Its totient is φ = 616623920640.

The previous prime is 668038611599. The next prime is 668038611619. The reversal of 668038611617 is 716116830866.

It can be written as a sum of positive squares in 6 ways, for example, as 71376602896 + 596662008721 = 267164^2 + 772439^2 .

It is not a de Polignac number, because 668038611617 - 2¹² = 668038607521 is a prime.

It is a super-2 number, since 2×668038611617² (a number of 24 digits) contains 22 as substring.

It is a Smith number, since the sum of its digits (53) coincides with the sum of the digits of its prime factors.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (668038611619) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 4476233 + ... + 4623065.

It is an arithmetic number, because the mean of its divisors is an integer number (60284240457).

Almost surely, 2^668038611617 is an apocalyptic number.

It is an amenable number.

668038611617 is a deficient number, since it is larger than the sum of its proper divisors (55372273867).

668038611617 is a wasteful number, since it uses less digits than its factorization.

668038611617 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 173780 (or 173767 counting only the distinct ones).

The product of its (nonzero) digits is 1741824, while the sum is 53.

The spelling of 668038611617 in words is "six hundred sixty-eight billion, thirty-eight million, six hundred eleven thousand, six hundred seventeen".