231249989 has 2 divisors, whose sum is σ = 231249990. Its totient is φ = 231249988.

The previous prime is 231249983. The next prime is 231250009. The reversal of 231249989 is 989942132.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 189750625 + 41499364 = 13775^2 + 6442^2 .

It is a cyclic number.

It is not a de Polignac number, because 231249989 - 2²⁴ = 214472773 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (231249983) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 115624994 + 115624995.

It is an arithmetic number, because the mean of its divisors is an integer number (115624995).

Almost surely, 2^231249989 is an apocalyptic number.

It is an amenable number.

231249989 is a deficient number, since it is larger than the sum of its proper divisors (1).

231249989 is an equidigital number, since it uses as much as digits as its factorization.

231249989 is an evil number, because the sum of its binary digits is even.

The product of its digits is 279936, while the sum is 47.

The square root of 231249989 is about 15206.9059640678. The cubic root of 231249989 is about 613.8005033637.

The spelling of 231249989 in words is "two hundred thirty-one million, two hundred forty-nine thousand, nine hundred eighty-nine".