18426 has 16 divisors (see below), whose sum is σ = 38304. Its totient is φ = 5904.

The previous prime is 18413. The next prime is 18427. The reversal of 18426 is 62481.

It is not an unprimeable number, because it can be changed into a prime (18427) by changing a digit.

18426 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, 181 + ... + 263.

It is an arithmetic number, because the mean of its divisors is an integer number (2394).

2¹⁸⁴²⁶ is an apocalyptic number.

18426 is the 111-st pentagonal number.

18426 is an abundant number, since it is smaller than the sum of its proper divisors (19878).

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 (19152).

18426 is a wasteful number, since it uses less digits than its factorization.

18426 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 125.

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

The square root of 18426 is about 135.7424031023. The cubic root of 18426 is about 26.4125514238.

It can be divided in two parts, 184 and 26, that added together give a triangular number (210 = T₂₀).

The spelling of 18426 in words is "eighteen thousand, four hundred twenty-six".