18890 has 8 divisors (see below), whose sum is σ = 34020. Its totient is φ = 7552.

The previous prime is 18869. The next prime is 18899. The reversal of 18890 is 9881.

It can be written as a sum of positive squares in 2 ways, for example, as 18769 + 121 = 137^2 + 11^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (18899) by changing a digit.

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 in 3 ways as a sum of consecutive naturals, for example, 935 + ... + 954.

2¹⁸⁸⁹⁰ is an apocalyptic number.

18890 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

18890 is a deficient number, since it is larger than the sum of its proper divisors (15130).

18890 is a wasteful number, since it uses less digits than its factorization.

18890 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1896.

The product of its (nonzero) digits is 576, while the sum is 26.

The square root of 18890 is about 137.4408963882. The cubic root of 18890 is about 26.6324213187.

Subtracting from 18890 its reverse (9881), we obtain a palindrome (9009).

The spelling of 18890 in words is "eighteen thousand, eight hundred ninety".