231135431 has 2 divisors, whose sum is σ = 231135432. Its totient is φ = 231135430.

The previous prime is 231135419. The next prime is 231135433. The reversal of 231135431 is 134531132.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 231135431 - 2⁶ = 231135367 is a prime.

It is a super-2 number, since 2×231135431² = 106847174927111522, which contains 22 as substring.

Together with 231135433, it forms a pair of twin primes.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 231135397 and 231135406.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (231135433) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 115567715 + 115567716.

It is an arithmetic number, because the mean of its divisors is an integer number (115567716).

Almost surely, 2^231135431 is an apocalyptic number.

231135431 is a deficient number, since it is larger than the sum of its proper divisors (1).

231135431 is an equidigital number, since it uses as much as digits as its factorization.

231135431 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1080, while the sum is 23.

The square root of 231135431 is about 15203.1388535394. The cubic root of 231135431 is about 613.6991305699.

Adding to 231135431 its reverse (134531132), we get a palindrome (365666563).

The spelling of 231135431 in words is "two hundred thirty-one million, one hundred thirty-five thousand, four hundred thirty-one".