18115115581 has 8 divisors (see below), whose sum is σ = 18185644800. Its totient is φ = 18044721408.

The previous prime is 18115115531. The next prime is 18115115591. The reversal of 18115115581 is 18551151181.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 18115115581 - 2⁹ = 18115115069 is a prime.

It is a super-2 number, since 2×18115115581² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 18115115581.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18115115521) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 239310 + ... + 305776.

It is an arithmetic number, because the mean of its divisors is an integer number (2273205600).

Almost surely, 2^18115115581 is an apocalyptic number.

It is an amenable number.

18115115581 is a deficient number, since it is larger than the sum of its proper divisors (70529219).

18115115581 is an equidigital number, since it uses as much as digits as its factorization.

18115115581 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 67523.

The product of its digits is 8000, while the sum is 37.

The spelling of 18115115581 in words is "eighteen billion, one hundred fifteen million, one hundred fifteen thousand, five hundred eighty-one".