18690 has 32 divisors (see below), whose sum is σ = 51840. Its totient is φ = 4224.

The previous prime is 18679. The next prime is 18691. The reversal of 18690 is 9681.

It is a super-2 number, since 2×18690² = 698632200, which contains 22 as substring.

It is a nialpdrome in base 12.

It is a self number, because there is not a number n which added to its sum of digits gives 18690.

It is not an unprimeable number, because it can be changed into a prime (18691) by changing a digit.

18690 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 15 ways as a sum of consecutive naturals, for example, 166 + ... + 254.

It is an arithmetic number, because the mean of its divisors is an integer number (1620).

2¹⁸⁶⁹⁰ is an apocalyptic number.

18690 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 18690, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25920).

18690 is an abundant number, since it is smaller than the sum of its proper divisors (33150).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

18690 is a wasteful number, since it uses less digits than its factorization.

18690 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 106.

The product of its (nonzero) digits is 432, while the sum is 24.

The square root of 18690 is about 136.7113748011. The cubic root of 18690 is about 26.5380963871.

Subtracting from 18690 its reverse (9681), we obtain a palindrome (9009).

It can be divided in two parts, 186 and 90, that added together give a triangular number (276 = T₂₃).

The spelling of 18690 in words is "eighteen thousand, six hundred ninety".