2161243011 has 4 divisors (see below), whose sum is σ = 2881657352. Its totient is φ = 1440828672.

The previous prime is 2161242977. The next prime is 2161243043. The reversal of 2161243011 is 1103421612.

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

It is not a de Polignac number, because 2161243011 - 2¹⁵ = 2161210243 is a prime.

It is a super-2 number, since 2×2161243011² = 9341942705192692242, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2161243111) 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, 360207166 + ... + 360207171.

It is an arithmetic number, because the mean of its divisors is an integer number (720414338).

Almost surely, 2^2161243011 is an apocalyptic number.

2161243011 is a deficient number, since it is larger than the sum of its proper divisors (720414341).

2161243011 is an equidigital number, since it uses as much as digits as its factorization.

2161243011 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 720414340.

The product of its (nonzero) digits is 288, while the sum is 21.

The square root of 2161243011 is about 46489.1709003290. The cubic root of 2161243011 is about 1292.9087281380.

Adding to 2161243011 its reverse (1103421612), we get a palindrome (3264664623).

The spelling of 2161243011 in words is "two billion, one hundred sixty-one million, two hundred forty-three thousand, eleven".