641518540 has 48 divisors (see below), whose sum is σ = 1455638688. Its totient is φ = 236081664.

The previous prime is 641518531. The next prime is 641518547. The reversal of 641518540 is 45815146.

It is a junction number, because it is equal to n+sod(n) for n = 641518496 and 641518505.

It is not an unprimeable number, because it can be changed into a prime (641518547) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 77439 + ... + 85321.

It is an arithmetic number, because the mean of its divisors is an integer number (30325806).

Almost surely, 2^641518540 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 641518540, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (727819344).

641518540 is an abundant number, since it is smaller than the sum of its proper divisors (814120148).

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

641518540 is a wasteful number, since it uses less digits than its factorization.

641518540 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8218 (or 8216 counting only the distinct ones).

The product of its (nonzero) digits is 19200, while the sum is 34.

The square root of 641518540 is about 25328.2162814518. The cubic root of 641518540 is about 862.4549199991.

The spelling of 641518540 in words is "six hundred forty-one million, five hundred eighteen thousand, five hundred forty".