115561139 has 2 divisors, whose sum is σ = 115561140. Its totient is φ = 115561138.

The previous prime is 115561123. The next prime is 115561141. The reversal of 115561139 is 931165511.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 115561139 - 2⁴ = 115561123 is a prime.

It is a Sophie Germain prime.

Together with 115561141, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (115561169) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 57780569 + 57780570.

It is an arithmetic number, because the mean of its divisors is an integer number (57780570).

Almost surely, 2^115561139 is an apocalyptic number.

115561139 is a deficient number, since it is larger than the sum of its proper divisors (1).

115561139 is an equidigital number, since it uses as much as digits as its factorization.

115561139 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 4050, while the sum is 32.

The square root of 115561139 is about 10749.9366974880. The cubic root of 115561139 is about 487.0840830381.

The spelling of 115561139 in words is "one hundred fifteen million, five hundred sixty-one thousand, one hundred thirty-nine".