646691172960 has 576 divisors, whose sum is σ = 2492424732672. Its totient is φ = 140260184064.

The previous prime is 646691172947. The next prime is 646691172977. The reversal of 646691172960 is 69271196646.

It is a self number, because there is not a number n which added to its sum of digits gives 646691172960.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 68697214 + ... + 68706626.

It is an arithmetic number, because the mean of its divisors is an integer number (4327126272).

Almost surely, 2^646691172960 is an apocalyptic number.

646691172960 is a gapful number since it is divisible by the number (60) 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 646691172960, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1246212366336).

646691172960 is an abundant number, since it is smaller than the sum of its proper divisors (1845733559712).

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

646691172960 is a wasteful number, since it uses less digits than its factorization.

646691172960 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9595 (or 9580 counting only the distinct ones).

The product of its (nonzero) digits is 5878656, while the sum is 57.

The spelling of 646691172960 in words is "six hundred forty-six billion, six hundred ninety-one million, one hundred seventy-two thousand, nine hundred sixty".