668889554868 has 144 divisors (see below), whose sum is σ = 1799349552000. Its totient is φ = 208785475584.

The previous prime is 668889554819. The next prime is 668889554873. The reversal of 668889554868 is 868455988866.

668889554868 is a `hidden beast` number, since 6 + 6 + 8 + 8 + 8 + 9 + 5 + 548 + 68 = 666.

It is a super-2 number, since 2×668889554868² (a number of 24 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 101821888 + ... + 101828456.

It is an arithmetic number, because the mean of its divisors is an integer number (12495483000).

Almost surely, 2^668889554868 is an apocalyptic number.

668889554868 is a gapful number since it is divisible by the number (68) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 668889554868, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (899674776000).

668889554868 is an abundant number, since it is smaller than the sum of its proper divisors (1130459997132).

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

668889554868 is a wasteful number, since it uses less digits than its factorization.

668889554868 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7414 (or 7409 counting only the distinct ones).

The product of its digits is 6370099200, while the sum is 81.

The spelling of 668889554868 in words is "six hundred sixty-eight billion, eight hundred eighty-nine million, five hundred fifty-four thousand, eight hundred sixty-eight".