231108509 has 2 divisors, whose sum is σ = 231108510. Its totient is φ = 231108508.

The previous prime is 231108499. The next prime is 231108547. The reversal of 231108509 is 905801132.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 184144900 + 46963609 = 13570^2 + 6853^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-231108509 is a prime.

It is a super-2 number, since 2×231108509² = 106822285864406162, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (231108589) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 115554254 + 115554255.

It is an arithmetic number, because the mean of its divisors is an integer number (115554255).

Almost surely, 2^231108509 is an apocalyptic number.

It is an amenable number.

231108509 is a deficient number, since it is larger than the sum of its proper divisors (1).

231108509 is an equidigital number, since it uses as much as digits as its factorization.

231108509 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2160, while the sum is 29.

The square root of 231108509 is about 15202.2534184903. The cubic root of 231108509 is about 613.6753023328.

The spelling of 231108509 in words is "two hundred thirty-one million, one hundred eight thousand, five hundred nine".