231211131 has 4 divisors (see below), whose sum is σ = 308281512. Its totient is φ = 154140752.

The previous prime is 231211109. The next prime is 231211153. The reversal of 231211131 is 131112132.

It is a happy number.

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

It is an interprime number because it is at equal distance from previous prime (231211109) and next prime (231211153).

It is a cyclic number.

It is not a de Polignac number, because 231211131 - 2⁹ = 231210619 is a prime.

It is a super-2 number, since 2×231211131² = 106917174196598322, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 231211131.

It is not an unprimeable number, because it can be changed into a prime (231211031) 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, 38535186 + ... + 38535191.

It is an arithmetic number, because the mean of its divisors is an integer number (77070378).

Almost surely, 2^231211131 is an apocalyptic number.

231211131 is a deficient number, since it is larger than the sum of its proper divisors (77070381).

231211131 is an equidigital number, since it uses as much as digits as its factorization.

231211131 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 77070380.

The product of its digits is 36, while the sum is 15.

The square root of 231211131 is about 15205.6282671911. The cubic root of 231211131 is about 613.7661215300.

Adding to 231211131 its reverse (131112132), we get a palindrome (362323263).

The spelling of 231211131 in words is "two hundred thirty-one million, two hundred eleven thousand, one hundred thirty-one".