668438415744 has 128 divisors (see below), whose sum is σ = 1978164564480. Its totient is φ = 198247311360.

The previous prime is 668438415737. The next prime is 668438415761. The reversal of 668438415744 is 447514834866.

It is a tau number, because it is divible by the number of its divisors (128).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1484959 + ... + 1882014.

It is an arithmetic number, because the mean of its divisors is an integer number (15454410660).

Almost surely, 2^668438415744 is an apocalyptic number.

668438415744 is a gapful number since it is divisible by the number (64) formed by its first and last digit.

It is an amenable number.

668438415744 is an abundant number, since it is smaller than the sum of its proper divisors (1309726148736).

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

668438415744 is a wasteful number, since it uses less digits than its factorization.

668438415744 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3367048 (or 3367036 counting only the distinct ones).

The product of its digits is 61931520, while the sum is 60.

The spelling of 668438415744 in words is "six hundred sixty-eight billion, four hundred thirty-eight million, four hundred fifteen thousand, seven hundred forty-four".