1231331231 has 4 divisors (see below), whose sum is σ = 1326049032. Its totient is φ = 1136613432.

The previous prime is 1231331221. The next prime is 1231331263. The reversal of 1231331231 is 1321331321.

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 1231331231 - 2²² = 1227136927 is a prime.

It is a super-2 number, since 2×1231331231² = 3032353200871950722, 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 (1231331201) 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, 47358881 + ... + 47358906.

It is an arithmetic number, because the mean of its divisors is an integer number (331512258).

Almost surely, 2^1231331231 is an apocalyptic number.

1231331231 is a deficient number, since it is larger than the sum of its proper divisors (94717801).

1231331231 is an equidigital number, since it uses as much as digits as its factorization.

1231331231 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 94717800.

The product of its digits is 324, while the sum is 20.

The square root of 1231331231 is about 35090.3295937784. The cubic root of 1231331231 is about 1071.8276711994.

Adding to 1231331231 its reverse (1321331321), we get a palindrome (2552662552).

The spelling of 1231331231 in words is "one billion, two hundred thirty-one million, three hundred thirty-one thousand, two hundred thirty-one".