641181320 has 64 divisors (see below), whose sum is σ = 1580040000. Its totient is φ = 232720128.

The previous prime is 641181241. The next prime is 641181337. The reversal of 641181320 is 23181146.

It is a super-2 number, since 2×641181320² = 822226970233884800, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (26).

It is a self number, because there is not a number n which added to its sum of digits gives 641181320.

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, 20231 + ... + 41129.

It is an arithmetic number, because the mean of its divisors is an integer number (24688125).

Almost surely, 2^641181320 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 641181320, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (790020000).

641181320 is an abundant number, since it is smaller than the sum of its proper divisors (938858680).

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

641181320 is a wasteful number, since it uses less digits than its factorization.

641181320 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20982 (or 20978 counting only the distinct ones).

The product of its (nonzero) digits is 1152, while the sum is 26.

The square root of 641181320 is about 25321.5584038582. The cubic root of 641181320 is about 862.3037744462.

The spelling of 641181320 in words is "six hundred forty-one million, one hundred eighty-one thousand, three hundred twenty".