218920 has 32 divisors (see below), whose sum is σ = 531720. Its totient is φ = 80640.

The previous prime is 218887. The next prime is 218923. The reversal of 218920 is 29812.

218920 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 4 ways, for example, as 60516 + 158404 = 246^2 + 398^2 .

It is a Smith number, since the sum of its digits (22) coincides with the sum of the digits of its prime factors.

It is a junction number, because it is equal to n+sod(n) for n = 218891 and 218900.

It is not an unprimeable number, because it can be changed into a prime (218923) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 310 + ... + 730.

2²¹⁸⁹²⁰ is an apocalyptic number.

218920 is a gapful number since it is divisible by the number (20) 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 218920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (265860).

218920 is an abundant number, since it is smaller than the sum of its proper divisors (312800).

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

218920 is a wasteful number, since it uses less digits than its factorization.

218920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 445 (or 441 counting only the distinct ones).

The product of its (nonzero) digits is 288, while the sum is 22.

The square root of 218920 is about 467.8888756959. Note that the first 4 decimals coincide. The cubic root of 218920 is about 60.2691611031.

It can be divided in two parts, 2189 and 20, that added together give a square (2209 = 47²).

The spelling of 218920 in words is "two hundred eighteen thousand, nine hundred twenty".