668956613 has 8 divisors (see below), whose sum is σ = 762792408. Its totient is φ = 581174784.

The previous prime is 668956591. The next prime is 668956637. The reversal of 668956613 is 316659866.

It can be written as a sum of positive squares in 4 ways, for example, as 113569 + 668843044 = 337^2 + 25862^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 668956613 - 2¹² = 668952517 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 (668956213) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1513256 + ... + 1513697.

It is an arithmetic number, because the mean of its divisors is an integer number (95349051).

Almost surely, 2^668956613 is an apocalyptic number.

It is an amenable number.

668956613 is a deficient number, since it is larger than the sum of its proper divisors (93835795).

668956613 is a wasteful number, since it uses less digits than its factorization.

668956613 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3026983.

The product of its digits is 1399680, while the sum is 50.

The square root of 668956613 is about 25864.1955799905. The cubic root of 668956613 is about 874.5795478756.

The spelling of 668956613 in words is "six hundred sixty-eight million, nine hundred fifty-six thousand, six hundred thirteen".