18505203855 has 8 divisors (see below), whose sum is σ = 29608326192. Its totient is φ = 9869442048.

The previous prime is 18505203779. The next prime is 18505203883. The reversal of 18505203855 is 55830250581.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 18505203855 - 2⁷ = 18505203727 is a prime.

It is a super-2 number, since 2×18505203855² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 616840114 + ... + 616840143.

It is an arithmetic number, because the mean of its divisors is an integer number (3701040774).

Almost surely, 2^18505203855 is an apocalyptic number.

18505203855 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

18505203855 is a deficient number, since it is larger than the sum of its proper divisors (11103122337).

18505203855 is a wasteful number, since it uses less digits than its factorization.

18505203855 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1233680265.

The product of its (nonzero) digits is 240000, while the sum is 42.

The spelling of 18505203855 in words is "eighteen billion, five hundred five million, two hundred three thousand, eight hundred fifty-five".