2161389231 has 32 divisors (see below), whose sum is σ = 3421598400. Its totient is φ = 1343692800.

The previous prime is 2161389199. The next prime is 2161389233. The reversal of 2161389231 is 1329831612.

2161389231 is a `hidden beast` number, since 2 + 1 + 613 + 8 + 9 + 2 + 31 = 666.

It is not a de Polignac number, because 2161389231 - 2⁵ = 2161389199 is a prime.

It is a super-2 number, since 2×2161389231² = 9343206815765542722, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2161389233) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 28431 + ... + 71631.

It is an arithmetic number, because the mean of its divisors is an integer number (106924950).

Almost surely, 2^2161389231 is an apocalyptic number.

2161389231 is a deficient number, since it is larger than the sum of its proper divisors (1260209169).

2161389231 is a wasteful number, since it uses less digits than its factorization.

2161389231 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 43336 (or 43330 counting only the distinct ones).

The product of its digits is 15552, while the sum is 36.

The square root of 2161389231 is about 46490.7434980341. The cubic root of 2161389231 is about 1292.9378849473.

The spelling of 2161389231 in words is "two billion, one hundred sixty-one million, three hundred eighty-nine thousand, two hundred thirty-one".