641660240000 has 320 divisors, whose sum is σ = 1821489155640. Its totient is φ = 222978048000.

The previous prime is 641660239967. The next prime is 641660240029. The reversal of 641660240000 is 42066146.

It can be written as a sum of positive squares in 20 ways, for example, as 488891827264 + 152768412736 = 699208^2 + 390856^2 .

It is a tau number, because it is divible by the number of its divisors (320).

It is an unprimeable number.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 17661854 + ... + 17698146.

Almost surely, 2^641660240000 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 641660240000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (910744577820).

641660240000 is an abundant number, since it is smaller than the sum of its proper divisors (1179828915640).

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

641660240000 is a wasteful number, since it uses less digits than its factorization.

641660240000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 36357 (or 36330 counting only the distinct ones).

The product of its (nonzero) digits is 6912, while the sum is 29.

The spelling of 641660240000 in words is "six hundred forty-one billion, six hundred sixty million, two hundred forty thousand".