220820 has 24 divisors (see below), whose sum is σ = 473928. Its totient is φ = 86400.
The previous prime is 220811. The next prime is 220841. The reversal of 220820 is 28022.
It can be written as a sum of positive squares in 4 ways, for example, as 21904 + 198916 = 148^2 + 446^2 .
It is a super-2 number, since 2×2208202 = 97522944800, which contains 22 as substring.
It is a junction number, because it is equal to n+sod(n) for n = 220795 and 220804.
It is a congruent number.
It is an unprimeable number.
220820 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 7 ways as a sum of consecutive naturals, for example, 1130 + ... + 1310.
It is an arithmetic number, because the mean of its divisors is an integer number (19747).
2220820 is an apocalyptic number.
220820 is a gapful number since it is divisible by the number (20) formed by its first and last digit.
It is an amenable number.
220820 is an abundant number, since it is smaller than the sum of its proper divisors (253108).
It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.
220820 is a wasteful number, since it uses less digits than its factorization.
220820 is an evil number, because the sum of its binary digits is even.
The sum of its prime factors is 251 (or 249 counting only the distinct ones).
The product of its (nonzero) digits is 64, while the sum is 14.
The square root of 220820 is about 469.9148859102. The cubic root of 220820 is about 60.4430171752.
Adding to 220820 its reverse (28022), we get a palindrome (248842).
The spelling of 220820 in words is "two hundred twenty thousand, eight hundred twenty".
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