231987109 has 2 divisors, whose sum is σ = 231987110. Its totient is φ = 231987108.

The previous prime is 231987103. The next prime is 231987113. The reversal of 231987109 is 901789132.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 221116900 + 10870209 = 14870^2 + 3297^2 .

It is a cyclic number.

It is not a de Polignac number, because 231987109 - 2³ = 231987101 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (231987101) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 115993554 + 115993555.

It is an arithmetic number, because the mean of its divisors is an integer number (115993555).

Almost surely, 2^231987109 is an apocalyptic number.

It is an amenable number.

231987109 is a deficient number, since it is larger than the sum of its proper divisors (1).

231987109 is an equidigital number, since it uses as much as digits as its factorization.

231987109 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 27216, while the sum is 40.

The square root of 231987109 is about 15231.1230380429. The cubic root of 231987109 is about 614.4519841114.

The spelling of 231987109 in words is "two hundred thirty-one million, nine hundred eighty-seven thousand, one hundred nine".