2181507904 has 28 divisors (see below), whose sum is σ = 4331398500. Its totient is φ = 1090131968.

The previous prime is 2181507899. The next prime is 2181507907. The reversal of 2181507904 is 4097051812.

It can be written as a sum of positive squares in 2 ways, for example, as 641102400 + 1540405504 = 25320^2 + 39248^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2181507907) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 115992 + ... + 133480.

Almost surely, 2^2181507904 is an apocalyptic number.

It is an amenable number.

2181507904 is a deficient number, since it is larger than the sum of its proper divisors (2149890596).

2181507904 is a wasteful number, since it uses less digits than its factorization.

2181507904 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19450 (or 19440 counting only the distinct ones).

The product of its (nonzero) digits is 20160, while the sum is 37.

The square root of 2181507904 is about 46706.6152059855. The cubic root of 2181507904 is about 1296.9371492345.

The spelling of 2181507904 in words is "two billion, one hundred eighty-one million, five hundred seven thousand, nine hundred four".