18573937581 has 16 divisors (see below), whose sum is σ = 25441363584. Its totient is φ = 12044746944.

The previous prime is 18573937553. The next prime is 18573937601.

18573937581 is nontrivially palindromic in base 10.

It is not a de Polignac number, because 18573937581 - 2⁷ = 18573937453 is a prime.

It is a super-2 number, since 2×18573937581² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18573937511) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 438520 + ... + 479006.

It is an arithmetic number, because the mean of its divisors is an integer number (1590085224).

Almost surely, 2^18573937581 is an apocalyptic number.

It is an amenable number.

18573937581 is a deficient number, since it is larger than the sum of its proper divisors (6867426003).

18573937581 is a wasteful number, since it uses less digits than its factorization.

18573937581 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 44660.

The product of its digits is 6350400, while the sum is 57.

The spelling of 18573937581 in words is "eighteen billion, five hundred seventy-three million, nine hundred thirty-seven thousand, five hundred eighty-one".