231959989 has 2 divisors, whose sum is σ = 231959990. Its totient is φ = 231959988.

The previous prime is 231959983. The next prime is 231960013. The reversal of 231959989 is 989959132.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 201157489 + 30802500 = 14183^2 + 5550^2 .

It is a cyclic number.

It is not a de Polignac number, because 231959989 - 2¹⁵ = 231927221 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (231959983) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 115979994 + 115979995.

It is an arithmetic number, because the mean of its divisors is an integer number (115979995).

Almost surely, 2^231959989 is an apocalyptic number.

It is an amenable number.

231959989 is a deficient number, since it is larger than the sum of its proper divisors (1).

231959989 is an equidigital number, since it uses as much as digits as its factorization.

231959989 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1574640, while the sum is 55.

The square root of 231959989 is about 15230.2327296729. The cubic root of 231959989 is about 614.4280394085.

The spelling of 231959989 in words is "two hundred thirty-one million, nine hundred fifty-nine thousand, nine hundred eighty-nine".