115665581 has 2 divisors, whose sum is σ = 115665582. Its totient is φ = 115665580.

The previous prime is 115665541. The next prime is 115665587. The reversal of 115665581 is 185566511.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 91508356 + 24157225 = 9566^2 + 4915^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-115665581 is a prime.

It is a super-2 number, since 2×115665581² = 26757053256135122, which contains 22 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (115665587) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 57832790 + 57832791.

It is an arithmetic number, because the mean of its divisors is an integer number (57832791).

Almost surely, 2^115665581 is an apocalyptic number.

It is an amenable number.

115665581 is a deficient number, since it is larger than the sum of its proper divisors (1).

115665581 is an equidigital number, since it uses as much as digits as its factorization.

115665581 is an evil number, because the sum of its binary digits is even.

The product of its digits is 36000, while the sum is 38.

The square root of 115665581 is about 10754.7933964349. The cubic root of 115665581 is about 487.2307780205.

The spelling of 115665581 in words is "one hundred fifteen million, six hundred sixty-five thousand, five hundred eighty-one".