668124817236 has 18 divisors (see below), whose sum is σ = 1688871065882. Its totient is φ = 222708272400.

The previous prime is 668124817189. The next prime is 668124817237. The reversal of 668124817236 is 632718421866.

It is a happy number.

668124817236 is a `hidden beast` number, since 6 + 68 + 1 + 2 + 481 + 72 + 36 = 666.

It can be written as a sum of positive squares in only one way, i.e., 663175694736 + 4949122500 = 814356^2 + 70350^2 .

It is a tau number, because it is divible by the number of its divisors (18).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (668124817237) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 9279511315 + ... + 9279511386.

Almost surely, 2^668124817236 is an apocalyptic number.

It is an amenable number.

668124817236 is an abundant number, since it is smaller than the sum of its proper divisors (1020746248646).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

668124817236 is a wasteful number, since it uses less digits than its factorization.

668124817236 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18559022711 (or 18559022706 counting only the distinct ones).

The product of its digits is 4644864, while the sum is 54.

The spelling of 668124817236 in words is "six hundred sixty-eight billion, one hundred twenty-four million, eight hundred seventeen thousand, two hundred thirty-six".