668891752464 has 320 divisors, whose sum is σ = 1951243723520. Its totient is φ = 196089569280.

The previous prime is 668891752457. The next prime is 668891752471. The reversal of 668891752464 is 464257198866.

It is an interprime number because it is at equal distance from previous prime (668891752457) and next prime (668891752471).

It is a super-2 number, since 2×668891752464² (a number of 24 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 668891752395 and 668891752404.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 279986982 + ... + 279989370.

It is an arithmetic number, because the mean of its divisors is an integer number (6097636636).

Almost surely, 2^668891752464 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 668891752464, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (975621861760).

668891752464 is an abundant number, since it is smaller than the sum of its proper divisors (1282351971056).

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

668891752464 is a wasteful number, since it uses less digits than its factorization.

668891752464 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2698 (or 2692 counting only the distinct ones).

The product of its digits is 139345920, while the sum is 66.

The spelling of 668891752464 in words is "six hundred sixty-eight billion, eight hundred ninety-one million, seven hundred fifty-two thousand, four hundred sixty-four".