16638 has 16 divisors (see below), whose sum is σ = 34560. Its totient is φ = 5336.

The previous prime is 16633. The next prime is 16649. The reversal of 16638 is 83661.

It is a plaindrome in base 11.

It is a nialpdrome in base 12.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (16631) 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, 253 + ... + 311.

It is an arithmetic number, because the mean of its divisors is an integer number (2160).

2¹⁶⁶³⁸ is an apocalyptic number.

16638 is an abundant number, since it is smaller than the sum of its proper divisors (17922).

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

It is a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (17280).

16638 is a wasteful number, since it uses less digits than its factorization.

16638 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 111.

The product of its digits is 864, while the sum is 24.

The square root of 16638 is about 128.9883715689. The cubic root of 16638 is about 25.5289943172.

The spelling of 16638 in words is "sixteen thousand, six hundred thirty-eight".