18905 has 8 divisors (see below), whose sum is σ = 24000.
Its totient is φ = 14256.
The previous prime is 18899. The next prime is 18911. The reversal of 18905 is 50981.
It is an interprime number because it is at equal distance from previous prime (18899) and next prime (18911).
It is a sphenic number, since it is the product of 3 distinct primes.
It is a cyclic number.
It is not a de Polignac number, because 18905 - 210 = 17881 is a prime.
It is an alternating number because its digits alternate between odd and even.
It is a Curzon number.
It is an unprimeable number.
It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5 + ... + 194.
It is an arithmetic number, because the mean of its divisors is an integer number (3000).
218905 is an apocalyptic number.
It is an amenable number.
18905 is a deficient number, since it is larger than the sum of its proper divisors (5095).
18905 is a wasteful number, since it uses less digits than its factorization.
18905 is an evil number, because the sum of its binary digits is even.
The sum of its prime factors is 223.
The product of its (nonzero) digits is 360, while the sum is 23.
The square root of 18905 is about 137.4954544703.
The cubic root of 18905 is about 26.6394687976.
It can be divided in two parts, 18 and 905, that multiplied together give a triangular number (16290 = T180).
The spelling of 18905 in words is "eighteen thousand, nine hundred five".