2161963872 has 120 divisors (see below), whose sum is σ = 6530410656. Its totient is φ = 701146368.

The previous prime is 2161963841. The next prime is 2161963877. The reversal of 2161963872 is 2783691612.

2161963872 is a `hidden beast` number, since 2 + 1 + 6 + 1 + 9 + 638 + 7 + 2 = 666.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2161963877) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 84633 + ... + 107175.

Almost surely, 2^2161963872 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 2161963872, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3265205328).

2161963872 is an abundant number, since it is smaller than the sum of its proper divisors (4368446784).

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

2161963872 is a wasteful number, since it uses less digits than its factorization.

2161963872 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22602 (or 22585 counting only the distinct ones).

The product of its digits is 217728, while the sum is 45.

The square root of 2161963872 is about 46496.9232530498. The cubic root of 2161963872 is about 1293.0524577530.

It can be divided in two parts, 21619 and 63872, that added together give a triangular number (85491 = T₄₁₃).

The spelling of 2161963872 in words is "two billion, one hundred sixty-one million, nine hundred sixty-three thousand, eight hundred seventy-two".