1231131089 has 2 divisors, whose sum is σ = 1231131090. Its totient is φ = 1231131088.

The previous prime is 1231131073. The next prime is 1231131091. The reversal of 1231131089 is 9801311321.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1200969025 + 30162064 = 34655^2 + 5492^2 .

It is a cyclic number.

It is not a de Polignac number, because 1231131089 - 2⁴ = 1231131073 is a prime.

Together with 1231131091, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (1231131029) 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, 615565544 + 615565545.

It is an arithmetic number, because the mean of its divisors is an integer number (615565545).

Almost surely, 2^1231131089 is an apocalyptic number.

It is an amenable number.

1231131089 is a deficient number, since it is larger than the sum of its proper divisors (1).

1231131089 is an equidigital number, since it uses as much as digits as its factorization.

1231131089 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1296, while the sum is 29.

The square root of 1231131089 is about 35087.4776665408. The cubic root of 1231131089 is about 1071.7695960170.

The spelling of 1231131089 in words is "one billion, two hundred thirty-one million, one hundred thirty-one thousand, eighty-nine".