1231131331 has 2 divisors, whose sum is σ = 1231131332. Its totient is φ = 1231131330.

The previous prime is 1231131283. The next prime is 1231131379. The reversal of 1231131331 is 1331311321.

It is a balanced prime because it is at equal distance from previous prime (1231131283) and next prime (1231131379).

It is an emirp because it is prime and its reverse (1331311321) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1231131331 - 2¹⁵ = 1231098563 is a prime.

It is a super-2 number, since 2×1231131331² = 3031368708339663122, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 1231131299 and 1231131308.

It is not a weakly prime, because it can be changed into another prime (1231131631) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 615565665 + 615565666.

It is an arithmetic number, because the mean of its divisors is an integer number (615565666).

Almost surely, 2^1231131331 is an apocalyptic number.

1231131331 is a deficient number, since it is larger than the sum of its proper divisors (1).

1231131331 is an equidigital number, since it uses as much as digits as its factorization.

1231131331 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 162, while the sum is 19.

The square root of 1231131331 is about 35087.4811150644. The cubic root of 1231131331 is about 1071.7696662419.

Adding to 1231131331 its reverse (1331311321), we get a palindrome (2562442652).

The spelling of 1231131331 in words is "one billion, two hundred thirty-one million, one hundred thirty-one thousand, three hundred thirty-one".