115818151581 has 72 divisors (see below), whose sum is σ = 188796482784. Its totient is φ = 67848243840.

The previous prime is 115818151573. The next prime is 115818151583. The reversal of 115818151581 is 185151818511.

115818151581 is a `hidden beast` number, since 1 + 1 + 5 + 8 + 18 + 1 + 51 + 581 = 666.

It is not a de Polignac number, because 115818151581 - 2³ = 115818151573 is a prime.

It is a super-2 number, since 2×115818151581² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (115818151583) by changing a digit.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 21275646 + ... + 21281088.

It is an arithmetic number, because the mean of its divisors is an integer number (2622173372).

Almost surely, 2^115818151581 is an apocalyptic number.

115818151581 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

115818151581 is a deficient number, since it is larger than the sum of its proper divisors (72978331203).

115818151581 is a wasteful number, since it uses less digits than its factorization.

115818151581 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5691 (or 5651 counting only the distinct ones).

The product of its digits is 64000, while the sum is 45.

The spelling of 115818151581 in words is "one hundred fifteen billion, eight hundred eighteen million, one hundred fifty-one thousand, five hundred eighty-one".