2121311231 has 4 divisors (see below), whose sum is σ = 2284489032. Its totient is φ = 1958133432.

The previous prime is 2121311219. The next prime is 2121311237. The reversal of 2121311231 is 1321131212.

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

It is a cyclic number.

It is not a de Polignac number, because 2121311231 - 2¹⁰ = 2121310207 is a prime.

It is a super-2 number, since 2×2121311231² = 8999922677533470722, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2121311237) 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, 81588881 + ... + 81588906.

It is an arithmetic number, because the mean of its divisors is an integer number (571122258).

Almost surely, 2^2121311231 is an apocalyptic number.

2121311231 is a deficient number, since it is larger than the sum of its proper divisors (163177801).

2121311231 is a wasteful number, since it uses less digits than its factorization.

2121311231 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 163177800.

The product of its digits is 72, while the sum is 17.

The square root of 2121311231 is about 46057.6945905893. The cubic root of 2121311231 is about 1284.8964535760.

Adding to 2121311231 its reverse (1321131212), we get a palindrome (3442442443).

The spelling of 2121311231 in words is "two billion, one hundred twenty-one million, three hundred eleven thousand, two hundred thirty-one".