2161522371 has 4 divisors (see below), whose sum is σ = 2882029832. Its totient is φ = 1441014912.

The previous prime is 2161522357. The next prime is 2161522411. The reversal of 2161522371 is 1732251612.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 2161522371 - 2⁷ = 2161522243 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2161522471) 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, 360253726 + ... + 360253731.

It is an arithmetic number, because the mean of its divisors is an integer number (720507458).

Almost surely, 2^2161522371 is an apocalyptic number.

2161522371 is a deficient number, since it is larger than the sum of its proper divisors (720507461).

2161522371 is an equidigital number, since it uses as much as digits as its factorization.

2161522371 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 720507460.

The product of its digits is 5040, while the sum is 30.

The square root of 2161522371 is about 46492.1753739272. The cubic root of 2161522371 is about 1292.9644324124.

Adding to 2161522371 its reverse (1732251612), we get a palindrome (3893773983).

The spelling of 2161522371 in words is "two billion, one hundred sixty-one million, five hundred twenty-two thousand, three hundred seventy-one".