668168902281 has 16 divisors (see below), whose sum is σ = 909921441024. Its totient is φ = 435932699904.

The previous prime is 668168902279. The next prime is 668168902361. The reversal of 668168902281 is 182209861866.

It is a happy number.

668168902281 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 668168902281 - 2¹ = 668168902279 is a prime.

It is a super-2 number, since 2×668168902281² (a number of 24 digits) contains 22 as substring.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (668168900281) 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, 1594321 + ... + 1969313.

It is an arithmetic number, because the mean of its divisors is an integer number (56870090064).

Almost surely, 2^668168902281 is an apocalyptic number.

It is an amenable number.

668168902281 is a deficient number, since it is larger than the sum of its proper divisors (241752538743).

668168902281 is a wasteful number, since it uses less digits than its factorization.

668168902281 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 387680.

The product of its (nonzero) digits is 3981312, while the sum is 57.

The spelling of 668168902281 in words is "six hundred sixty-eight billion, one hundred sixty-eight million, nine hundred two thousand, two hundred eighty-one".