18505000553 has 4 divisors (see below), whose sum is σ = 19928462148. Its totient is φ = 17081538960.

The previous prime is 18505000537. The next prime is 18505000573. The reversal of 18505000553 is 35500050581.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 35500050581 = 4201 ⋅8450381.

It can be written as a sum of positive squares in 2 ways, for example, as 4526194729 + 13978805824 = 67277^2 + 118232^2 .

It is a cyclic number.

It is not a de Polignac number, because 18505000553 - 2⁴ = 18505000537 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (18505000573) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 711730778 + ... + 711730803.

It is an arithmetic number, because the mean of its divisors is an integer number (4982115537).

Almost surely, 2^18505000553 is an apocalyptic number.

18505000553 is a gapful number since it is divisible by the number (13) formed by its first and last digit.

It is an amenable number.

18505000553 is a deficient number, since it is larger than the sum of its proper divisors (1423461595).

18505000553 is a wasteful number, since it uses less digits than its factorization.

18505000553 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1423461594.

The product of its (nonzero) digits is 15000, while the sum is 32.

The spelling of 18505000553 in words is "eighteen billion, five hundred five million, five hundred fifty-three", and thus it is an aban number.