231121031 has 2 divisors, whose sum is σ = 231121032. Its totient is φ = 231121030.

The previous prime is 231121021. The next prime is 231121061. The reversal of 231121031 is 130121132.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 231121031 - 2¹⁰ = 231120007 is a prime.

It is a super-2 number, since 2×231121031² = 106833861941005922, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 231120997 and 231121015.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (231121021) 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, 115560515 + 115560516.

It is an arithmetic number, because the mean of its divisors is an integer number (115560516).

Almost surely, 2^231121031 is an apocalyptic number.

231121031 is a deficient number, since it is larger than the sum of its proper divisors (1).

231121031 is an equidigital number, since it uses as much as digits as its factorization.

231121031 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 36, while the sum is 14.

The square root of 231121031 is about 15202.6652597497. The cubic root of 231121031 is about 613.6863855874.

Adding to 231121031 its reverse (130121132), we get a palindrome (361242163).

The spelling of 231121031 in words is "two hundred thirty-one million, one hundred twenty-one thousand, thirty-one".