231111131 has 4 divisors (see below), whose sum is σ = 232308792. Its totient is φ = 229913472.

The previous prime is 231111109. The next prime is 231111149. The reversal of 231111131 is 131111132.

It is a happy number.

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 231111131 - 2¹⁰ = 231110107 is a prime.

It is a super-2 number, since 2×231111131² = 106824709744198322, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (231111161) 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, 598541 + ... + 598926.

It is an arithmetic number, because the mean of its divisors is an integer number (58077198).

Almost surely, 2^231111131 is an apocalyptic number.

231111131 is a deficient number, since it is larger than the sum of its proper divisors (1197661).

231111131 is a wasteful number, since it uses less digits than its factorization.

231111131 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1197660.

The product of its digits is 18, while the sum is 14.

The square root of 231111131 is about 15202.3396554609. The cubic root of 231111131 is about 613.6776231050.

Adding to 231111131 its reverse (131111132), we get a palindrome (362222263).

Subtracting from 231111131 its reverse (131111132), we obtain a palindrome (99999999).

It can be divided in two parts, 23111 and 1131, that added together give a palindrome (24242).

The spelling of 231111131 in words is "two hundred thirty-one million, one hundred eleven thousand, one hundred thirty-one".