115865305581 has 16 divisors (see below), whose sum is σ = 155242342400. Its totient is φ = 76866012720.

The previous prime is 115865305547. The next prime is 115865305651. The reversal of 115865305581 is 185503568511.

It is not a de Polignac number, because 115865305581 - 2¹⁰ = 115865304557 is a prime.

It is a super-2 number, since 2×115865305581² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 115865305581.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (115865305541) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 7615620 + ... + 7630818.

It is an arithmetic number, because the mean of its divisors is an integer number (9702646400).

Almost surely, 2^115865305581 is an apocalyptic number.

It is an amenable number.

115865305581 is a deficient number, since it is larger than the sum of its proper divisors (39377036819).

115865305581 is a wasteful number, since it uses less digits than its factorization.

115865305581 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 27456.

The product of its (nonzero) digits is 720000, while the sum is 48.

The spelling of 115865305581 in words is "one hundred fifteen billion, eight hundred sixty-five million, three hundred five thousand, five hundred eighty-one".