18920 has 32 divisors (see below), whose sum is σ = 47520. Its totient is φ = 6720.

The previous prime is 18919. The next prime is 18947. The reversal of 18920 is 2981.

18920 = T₁₆ + T₁₇ + ... + T₄₈.

It is a Smith number, since the sum of its digits (20) coincides with the sum of the digits of its prime factors.

It is a Harshad number since it is a multiple of its sum of digits (20).

It is a junction number, because it is equal to n+sod(n) for n = 18892 and 18901.

It is an unprimeable number.

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 7 ways as a sum of consecutive naturals, for example, 419 + ... + 461.

It is an arithmetic number, because the mean of its divisors is an integer number (1485).

2¹⁸⁹²⁰ is an apocalyptic number.

18920 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 18920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (23760).

18920 is an abundant number, since it is smaller than the sum of its proper divisors (28600).

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

18920 is a wasteful number, since it uses less digits than its factorization.

18920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 65 (or 61 counting only the distinct ones).

The product of its (nonzero) digits is 144, while the sum is 20.

The square root of 18920 is about 137.5499909124. The cubic root of 18920 is about 26.6465125495.

18920 divided by its sum of digits (20) gives a triangular number (946 = T₄₃).

The spelling of 18920 in words is "eighteen thousand, nine hundred twenty".