668212616 has 8 divisors (see below), whose sum is σ = 1252898670. Its totient is φ = 334106304.

The previous prime is 668212613. The next prime is 668212627. The reversal of 668212616 is 616212866.

It can be written as a sum of positive squares in only one way, i.e., 540748516 + 127464100 = 23254^2 + 11290^2 .

It is a tau number, because it is divible by the number of its divisors (8).

It is a self number, because there is not a number n which added to its sum of digits gives 668212616.

It is not an unprimeable number, because it can be changed into a prime (668212613) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 41763281 + ... + 41763296.

Almost surely, 2^668212616 is an apocalyptic number.

It is an amenable number.

668212616 is a deficient number, since it is larger than the sum of its proper divisors (584686054).

668212616 is a wasteful number, since it uses less digits than its factorization.

668212616 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 83526583 (or 83526579 counting only the distinct ones).

The product of its digits is 41472, while the sum is 38.

The square root of 668212616 is about 25849.8088194091. The cubic root of 668212616 is about 874.2551990208.

The spelling of 668212616 in words is "six hundred sixty-eight million, two hundred twelve thousand, six hundred sixteen".