16557 has 4 divisors (see below), whose sum is σ = 22080. Its totient is φ = 11036.

The previous prime is 16553. The next prime is 16561. The reversal of 16557 is 75561.

16557 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

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 an interprime number because it is at equal distance from previous prime (16553) and next prime (16561).

It is a cyclic number.

It is not a de Polignac number, because 16557 - 2² = 16553 is a prime.

It is a D-number.

16557 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (16553) 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, 2757 + ... + 2762.

It is an arithmetic number, because the mean of its divisors is an integer number (5520).

2¹⁶⁵⁵⁷ is an apocalyptic number.

It is an amenable number.

16557 is a deficient number, since it is larger than the sum of its proper divisors (5523).

16557 is an equidigital number, since it uses as much as digits as its factorization.

16557 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5522.

The product of its digits is 1050, while the sum is 24.

The square root of 16557 is about 128.6740066991. The cubic root of 16557 is about 25.4874986781.

It can be divided in two parts, 165 and 57, that added together give a palindrome (222).

The spelling of 16557 in words is "sixteen thousand, five hundred fifty-seven".