18557 has 8 divisors (see below), whose sum is σ = 23232. Its totient is φ = 14400.

The previous prime is 18553. The next prime is 18583. The reversal of 18557 is 75581.

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

It is a cyclic number.

It is not a de Polignac number, because 18557 - 2² = 18553 is a prime.

It is an Ulam number.

It is a zygodrome in base 3.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18553) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 44 + ... + 197.

It is an arithmetic number, because the mean of its divisors is an integer number (2904).

2¹⁸⁵⁵⁷ is an apocalyptic number.

It is an amenable number.

18557 is a deficient number, since it is larger than the sum of its proper divisors (4675).

18557 is a wasteful number, since it uses less digits than its factorization.

18557 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 259.

The product of its digits is 1400, while the sum is 26.

The square root of 18557 is about 136.2240801033. The cubic root of 18557 is about 26.4749971838.

It can be divided in two parts, 185 and 57, that added together give a palindrome (242).

The spelling of 18557 in words is "eighteen thousand, five hundred fifty-seven".