2161871243 has 24 divisors (see below), whose sum is σ = 2617671168. Its totient is φ = 1748722608.

The previous prime is 2161871237. The next prime is 2161871287. The reversal of 2161871243 is 3421781612.

It is not a de Polignac number, because 2161871243 - 2¹⁴ = 2161854859 is a prime.

It is not an unprimeable number, because it can be changed into a prime (2161871233) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 713630 + ... + 716652.

It is an arithmetic number, because the mean of its divisors is an integer number (109069632).

Almost surely, 2^2161871243 is an apocalyptic number.

2161871243 is a deficient number, since it is larger than the sum of its proper divisors (455799925).

2161871243 is a wasteful number, since it uses less digits than its factorization.

2161871243 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3351 (or 3332 counting only the distinct ones).

The product of its digits is 16128, while the sum is 35.

The square root of 2161871243 is about 46495.9271657207. The cubic root of 2161871243 is about 1293.0339906132.

The spelling of 2161871243 in words is "two billion, one hundred sixty-one million, eight hundred seventy-one thousand, two hundred forty-three".