641520144 has 30 divisors (see below), whose sum is σ = 1795365806. Its totient is φ = 213840000.

The previous prime is 641520137. The next prime is 641520179. The reversal of 641520144 is 441025146.

641520144 is a `hidden beast` number, since 6 + 415 + 201 + 44 = 666.

It can be written as a sum of positive squares in only one way, i.e., 416160000 + 225360144 = 20400^2 + 15012^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 2227357 + ... + 2227644.

Almost surely, 2^641520144 is an apocalyptic number.

It is an amenable number.

641520144 is an abundant number, since it is smaller than the sum of its proper divisors (1153845662).

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

641520144 is a wasteful number, since it uses less digits than its factorization.

641520144 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4455015 (or 4455006 counting only the distinct ones).

The product of its (nonzero) digits is 3840, while the sum is 27.

The square root of 641520144 is about 25328.2479457226. The cubic root of 641520144 is about 862.4556388022.

The spelling of 641520144 in words is "six hundred forty-one million, five hundred twenty thousand, one hundred forty-four".