668940397351 has 16 divisors (see below), whose sum is σ = 689817577248. Its totient is φ = 648475200000.

The previous prime is 668940397313. The next prime is 668940397417. The reversal of 668940397351 is 153793049866.

It is a cyclic number.

It is not a de Polignac number, because 668940397351 - 2¹¹ = 668940395303 is a prime.

It is a super-2 number, since 2×668940397351² (a number of 24 digits) contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 668940397351.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (668940397051) 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, 678976 + ... + 1341226.

It is an arithmetic number, because the mean of its divisors is an integer number (43113598578).

Almost surely, 2^668940397351 is an apocalyptic number.

668940397351 is a deficient number, since it is larger than the sum of its proper divisors (20877179897).

668940397351 is a wasteful number, since it uses less digits than its factorization.

668940397351 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 662562.

The product of its (nonzero) digits is 29393280, while the sum is 61.

The spelling of 668940397351 in words is "six hundred sixty-eight billion, nine hundred forty million, three hundred ninety-seven thousand, three hundred fifty-one".