641521632 has 96 divisors (see below), whose sum is σ = 1724405760. Its totient is φ = 208762880.

The previous prime is 641521631. The next prime is 641521667. The reversal of 641521632 is 236125146.

It is a tau number, because it is divible by the number of its divisors (96).

It is a self number, because there is not a number n which added to its sum of digits gives 641521632.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (641521631) 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, 1081528 + ... + 1082120.

It is an arithmetic number, because the mean of its divisors is an integer number (17962560).

Almost surely, 2^641521632 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 641521632, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (862202880).

641521632 is an abundant number, since it is smaller than the sum of its proper divisors (1082884128).

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

641521632 is a wasteful number, since it uses less digits than its factorization.

641521632 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 856 (or 848 counting only the distinct ones).

The product of its digits is 8640, while the sum is 30.

The square root of 641521632 is about 25328.2773200232. The cubic root of 641521632 is about 862.4563056210.

Adding to 641521632 its reverse (236125146), we get a palindrome (877646778).

The spelling of 641521632 in words is "six hundred forty-one million, five hundred twenty-one thousand, six hundred thirty-two".