18742 has 4 divisors (see below), whose sum is σ = 28116. Its totient is φ = 9370.

The previous prime is 18731. The next prime is 18743. The reversal of 18742 is 24781.

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

It is a Smith number, since the sum of its digits (22) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a plaindrome in base 8.

It is a zygodrome in base 8.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18743) by changing a digit.

18742 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4684 + ... + 4687.

It is an arithmetic number, because the mean of its divisors is an integer number (7029).

2¹⁸⁷⁴² is an apocalyptic number.

18742 is a deficient number, since it is larger than the sum of its proper divisors (9374).

18742 is an equidigital number, since it uses as much as digits as its factorization.

18742 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9373.

The product of its digits is 448, while the sum is 22.

The square root of 18742 is about 136.9014243900. The cubic root of 18742 is about 26.5626853505.

The spelling of 18742 in words is "eighteen thousand, seven hundred forty-two".