18117511253 has 4 divisors (see below), whose sum is σ = 18538848768. Its totient is φ = 17696173740.

The previous prime is 18117511229. The next prime is 18117511273. The reversal of 18117511253 is 35211571181.

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 18117511253 - 2¹² = 18117507157 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18117511273) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 210668693 + ... + 210668778.

It is an arithmetic number, because the mean of its divisors is an integer number (4634712192).

Almost surely, 2^18117511253 is an apocalyptic number.

It is an amenable number.

18117511253 is a deficient number, since it is larger than the sum of its proper divisors (421337515).

18117511253 is an equidigital number, since it uses as much as digits as its factorization.

18117511253 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 421337514.

The product of its digits is 8400, while the sum is 35.

The spelling of 18117511253 in words is "eighteen billion, one hundred seventeen million, five hundred eleven thousand, two hundred fifty-three".