20220 has 24 divisors (see below), whose sum is σ = 56784.
Its totient is φ = 5376.
The previous prime is 20219. The next prime is 20231. The reversal of 20220 is 2202.
20220 is nontrivially palindromic in base 8.
It is a Harshad number since it is a multiple of its sum of digits (6).
It is a super Niven number, because it is divisible the sum of any subset of its (nonzero) digits.
It is a nialpdrome in base 12.
It is a junction number, because it is equal to n+sod(n) for n = 20199 and 20208.
It is a congruent 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, 109 + ... + 228.
It is an arithmetic number, because the mean of its divisors is an integer number (2366).
220220 is an apocalyptic number.
20220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.
It is an amenable number.
20220 is an abundant number, since it is smaller than the sum of its proper divisors (36564).
It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.
It is a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28392).
20220 is a wasteful number, since it uses less digits than its factorization.
With its successor (20221) it forms an eRAP, since the sums of their prime factors are consecutive (349 and 350).
20220 is an evil number, because the sum of its binary digits is even.
The sum of its prime factors is 349 (or 347 counting only the distinct ones).
The product of its (nonzero) digits is 8, while the sum is 6.
The square root of 20220 is about 142.1970463828.
The cubic root of 20220 is about 27.2433420875.
Adding to 20220 its reverse (2202), we get a palindrome (22422).
It can be divided in two parts, 202 and 20, that added together give a palindrome (222).
The spelling of 20220 in words is "twenty thousand, two hundred twenty", and thus it is an iban number.