641894965440 has 112 divisors (see below), whose sum is σ = 2040495353088. Its totient is φ = 170963794944.

The previous prime is 641894965429. The next prime is 641894965499. The reversal of 641894965440 is 44569498146.

641894965440 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a Harshad number since it is a multiple of its sum of digits (60).

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, 383859 + ... + 1196301.

Almost surely, 2^641894965440 is an apocalyptic number.

641894965440 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 641894965440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1020247676544).

641894965440 is an abundant number, since it is smaller than the sum of its proper divisors (1398600387648).

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

641894965440 is a wasteful number, since it uses less digits than its factorization.

641894965440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 813286 (or 813276 counting only the distinct ones).

The product of its (nonzero) digits is 29859840, while the sum is 60.

The spelling of 641894965440 in words is "six hundred forty-one billion, eight hundred ninety-four million, nine hundred sixty-five thousand, four hundred forty".