2181855684 has 24 divisors (see below), whose sum is σ = 5390467488. Its totient is φ = 684503680.

The previous prime is 2181855659. The next prime is 2181855721. The reversal of 2181855684 is 4865581812.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5347482 + ... + 5347889.

It is an arithmetic number, because the mean of its divisors is an integer number (224602812).

Almost surely, 2^2181855684 is an apocalyptic number.

It is an amenable number.

2181855684 is an abundant number, since it is smaller than the sum of its proper divisors (3208611804).

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

2181855684 is a wasteful number, since it uses less digits than its factorization.

2181855684 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10695395 (or 10695393 counting only the distinct ones).

The product of its digits is 614400, while the sum is 48.

The square root of 2181855684 is about 46710.3380848394. The cubic root of 2181855684 is about 1297.0060656072.

The spelling of 2181855684 in words is "two billion, one hundred eighty-one million, eight hundred fifty-five thousand, six hundred eighty-four".