18442 has 4 divisors (see below), whose sum is σ = 27666. Its totient is φ = 9220.

The previous prime is 18439. The next prime is 18443. The reversal of 18442 is 24481.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 11881 + 6561 = 109^2 + 81^2 .

It is not an unprimeable number, because it can be changed into a prime (18443) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4609 + ... + 4612.

2¹⁸⁴⁴² is an apocalyptic number.

18442 is a deficient number, since it is larger than the sum of its proper divisors (9224).

18442 is an equidigital number, since it uses as much as digits as its factorization.

18442 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9223.

The product of its digits is 256, while the sum is 19.

The square root of 18442 is about 135.8013254722. The cubic root of 18442 is about 26.4201942213.

The spelling of 18442 in words is "eighteen thousand, four hundred forty-two".