18406 has 4 divisors (see below), whose sum is σ = 27612. Its totient is φ = 9202.

The previous prime is 18401. The next prime is 18413. The reversal of 18406 is 60481.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 60481 = 31 ⋅1951.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18401) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4600 + ... + 4603.

It is an arithmetic number, because the mean of its divisors is an integer number (6903).

2¹⁸⁴⁰⁶ is an apocalyptic number.

18406 is a deficient number, since it is larger than the sum of its proper divisors (9206).

18406 is an equidigital number, since it uses as much as digits as its factorization.

18406 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9205.

The product of its (nonzero) digits is 192, while the sum is 19.

The square root of 18406 is about 135.6687141533. The cubic root of 18406 is about 26.4029917026.

Adding to 18406 its reverse (60481), we get a palindrome (78887).

It can be divided in two parts, 18 and 406, that added together give a palindrome (424).

The spelling of 18406 in words is "eighteen thousand, four hundred six".