1231331089 has 2 divisors, whose sum is σ = 1231331090. Its totient is φ = 1231331088.

The previous prime is 1231331071. The next prime is 1231331099. The reversal of 1231331089 is 9801331321.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1146838225 + 84492864 = 33865^2 + 9192^2 .

It is a cyclic number.

It is not a de Polignac number, because 1231331089 - 2¹¹ = 1231329041 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1231331089.

It is not a weakly prime, because it can be changed into another prime (1231331099) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 615665544 + 615665545.

It is an arithmetic number, because the mean of its divisors is an integer number (615665545).

Almost surely, 2^1231331089 is an apocalyptic number.

It is an amenable number.

1231331089 is a deficient number, since it is larger than the sum of its proper divisors (1).

1231331089 is an equidigital number, since it uses as much as digits as its factorization.

1231331089 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3888, while the sum is 31.

The square root of 1231331089 is about 35090.3275704289. The cubic root of 1231331089 is about 1071.8276299975.

The spelling of 1231331089 in words is "one billion, two hundred thirty-one million, three hundred thirty-one thousand, eighty-nine".