18115739581 has 8 divisors (see below), whose sum is σ = 18158079744. Its totient is φ = 18073450560.

The previous prime is 18115739519. The next prime is 18115739611. The reversal of 18115739581 is 18593751181.

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 18115739581 - 2²³ = 18107350973 is a prime.

It is a super-2 number, since 2×18115739581² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18115739501) 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, 748390 + ... + 772216.

It is an arithmetic number, because the mean of its divisors is an integer number (2269759968).

Almost surely, 2^18115739581 is an apocalyptic number.

It is an amenable number.

18115739581 is a deficient number, since it is larger than the sum of its proper divisors (42340163).

18115739581 is an equidigital number, since it uses as much as digits as its factorization.

18115739581 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 25571.

The product of its digits is 302400, while the sum is 49.

The spelling of 18115739581 in words is "eighteen billion, one hundred fifteen million, seven hundred thirty-nine thousand, five hundred eighty-one".