641863781160 has 384 divisors, whose sum is σ = 2347955527680. Its totient is φ = 139697091072.

The previous prime is 641863781159. The next prime is 641863781173. The reversal of 641863781160 is 61187368146.

It is a happy number.

It is a super-2 number, since 2×641863781160² (a number of 24 digits) contains 22 as substring.

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, 30147879 + ... + 30169161.

It is an arithmetic number, because the mean of its divisors is an integer number (6114467520).

Almost surely, 2^641863781160 is an apocalyptic number.

641863781160 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 641863781160, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1173977763840).

641863781160 is an abundant number, since it is smaller than the sum of its proper divisors (1706091746520).

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

641863781160 is a wasteful number, since it uses less digits than its factorization.

641863781160 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21557 (or 21546 counting only the distinct ones).

The product of its (nonzero) digits is 1161216, while the sum is 51.

The spelling of 641863781160 in words is "six hundred forty-one billion, eight hundred sixty-three million, seven hundred eighty-one thousand, one hundred sixty".