2161780964 has 48 divisors (see below), whose sum is σ = 4387891200. Its totient is φ = 912746016.

The previous prime is 2161780961. The next prime is 2161780969. The reversal of 2161780964 is 4690871612.

It is not an unprimeable number, because it can be changed into a prime (2161780961) 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, 1456967 + ... + 1458449.

It is an arithmetic number, because the mean of its divisors is an integer number (91414400).

Almost surely, 2^2161780964 is an apocalyptic number.

It is an amenable number.

2161780964 is an abundant number, since it is smaller than the sum of its proper divisors (2226110236).

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

2161780964 is a wasteful number, since it uses less digits than its factorization.

2161780964 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2232 (or 2230 counting only the distinct ones).

The product of its (nonzero) digits is 145152, while the sum is 44.

The square root of 2161780964 is about 46494.9563286170. The cubic root of 2161780964 is about 1293.0159914777.

The spelling of 2161780964 in words is "two billion, one hundred sixty-one million, seven hundred eighty thousand, nine hundred sixty-four".