668278105680 has 40 divisors (see below), whose sum is σ = 2071662128352. Its totient is φ = 178207494784.

The previous prime is 668278105673. The next prime is 668278105717. The reversal of 668278105680 is 86501872866.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (40).

It is a self number, because there is not a number n which added to its sum of digits gives 668278105680.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1392245814 + ... + 1392246293.

Almost surely, 2^668278105680 is an apocalyptic number.

668278105680 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

668278105680 is an abundant number, since it is smaller than the sum of its proper divisors (1403384022672).

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

668278105680 is a wasteful number, since it uses less digits than its factorization.

668278105680 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2784492123 (or 2784492117 counting only the distinct ones).

The product of its (nonzero) digits is 7741440, while the sum is 57.

The spelling of 668278105680 in words is "six hundred sixty-eight billion, two hundred seventy-eight million, one hundred five thousand, six hundred eighty".