18181053517 has 4 divisors (see below), whose sum is σ = 19833876576. Its totient is φ = 16528230460.

The previous prime is 18181053511. The next prime is 18181053587. The reversal of 18181053517 is 71535018181.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 18181053517 - 2³ = 18181053509 is a prime.

It is a Smith number, since the sum of its digits (40) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

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 18181053517.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18181053511) 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 3 ways as a sum of consecutive naturals, for example, 826411513 + ... + 826411534.

It is an arithmetic number, because the mean of its divisors is an integer number (4958469144).

Almost surely, 2^18181053517 is an apocalyptic number.

It is an amenable number.

18181053517 is a deficient number, since it is larger than the sum of its proper divisors (1652823059).

18181053517 is a wasteful number, since it uses less digits than its factorization.

18181053517 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1652823058.

The product of its (nonzero) digits is 33600, while the sum is 40.

The spelling of 18181053517 in words is "eighteen billion, one hundred eighty-one million, fifty-three thousand, five hundred seventeen".