18505055550 has 24 divisors (see below), whose sum is σ = 45892538136. Its totient is φ = 4934681440.

The previous prime is 18505055549. The next prime is 18505055561. The reversal of 18505055550 is 5555050581.

It is a junction number, because it is equal to n+sod(n) for n = 18505055499 and 18505055508.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 61683369 + ... + 61683668.

It is an arithmetic number, because the mean of its divisors is an integer number (1912189089).

Almost surely, 2^18505055550 is an apocalyptic number.

18505055550 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

18505055550 is an abundant number, since it is smaller than the sum of its proper divisors (27387482586).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

18505055550 is a wasteful number, since it uses less digits than its factorization.

18505055550 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 123367052 (or 123367047 counting only the distinct ones).

The product of its (nonzero) digits is 125000, while the sum is 39.

The spelling of 18505055550 in words is "eighteen billion, five hundred five million, fifty-five thousand, five hundred fifty".