18642 has 16 divisors (see below), whose sum is σ = 40320. Its totient is φ = 5712.

The previous prime is 18637. The next prime is 18661. The reversal of 18642 is 24681.

It is a plaindrome in base 15.

It is a nialpdrome in base 8 and base 13.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 18642.

It is an unprimeable number.

18642 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 42 + ... + 197.

It is an arithmetic number, because the mean of its divisors is an integer number (2520).

2¹⁸⁶⁴² is an apocalyptic number.

18642 is an abundant number, since it is smaller than the sum of its proper divisors (21678).

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 (20160).

18642 is a wasteful number, since it uses less digits than its factorization.

18642 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 257.

The product of its digits is 384, while the sum is 21.

The square root of 18642 is about 136.5357096147. The cubic root of 18642 is about 26.5153583690.

The spelling of 18642 in words is "eighteen thousand, six hundred forty-two".