641988144 has 120 divisors (see below), whose sum is σ = 2142696192. Its totient is φ = 175443840.

The previous prime is 641988103. The next prime is 641988161. The reversal of 641988144 is 441889146.

It is a nude number because it is divisible by every one of its digits.

It is a self number, because there is not a number n which added to its sum of digits gives 641988144.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 9339 + ... + 37029.

Almost surely, 2^641988144 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 641988144, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1071348096).

641988144 is an abundant number, since it is smaller than the sum of its proper divisors (1500708048).

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

641988144 is a wasteful number, since it uses less digits than its factorization.

641988144 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 27735 (or 27726 counting only the distinct ones).

The product of its digits is 221184, while the sum is 45.

The square root of 641988144 is about 25337.4849580616. The cubic root of 641988144 is about 862.6653132403.

The spelling of 641988144 in words is "six hundred forty-one million, nine hundred eighty-eight thousand, one hundred forty-four".