641256652800 has 660 divisors, whose sum is σ = 2391390244056. Its totient is φ = 169869312000.

The previous prime is 641256652789. The next prime is 641256652801. The reversal of 641256652800 is 8256652146.

641256652800 is a `hidden beast` number, since 6 + 4 + 1 + 2 + 566 + 5 + 2 + 80 + 0 = 666.

It is a super-2 number, since 2×641256652800² (a number of 24 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (641256652801) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 29 ways as a sum of consecutive naturals, for example, 4246732725 + ... + 4246732875.

Almost surely, 2^641256652800 is an apocalyptic number.

641256652800 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 641256652800, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1195695122028).

641256652800 is an abundant number, since it is smaller than the sum of its proper divisors (1750133591256).

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

641256652800 is an frugal number, since it uses more digits than its factorization.

641256652800 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 215 (or 161 counting only the distinct ones).

The product of its (nonzero) digits is 691200, while the sum is 45.

The spelling of 641256652800 in words is "six hundred forty-one billion, two hundred fifty-six million, six hundred fifty-two thousand, eight hundred".