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8420 = 225421
BaseRepresentation
bin10000011100100
3102112212
42003210
5232140
6102552
733356
oct20344
912485
108420
116365
124a58
133aa9
1430d6
152765
hex20e4

8420 has 12 divisors (see below), whose sum is σ = 17724. Its totient is φ = 3360.

The previous prime is 8419. The next prime is 8423. The reversal of 8420 is 248.

It can be written as a sum of positive squares in 2 ways, for example, as 1024 + 7396 = 32^2 + 86^2 .

It is a hoax number, since the sum of its digits (14) coincides with the sum of the digits of its distinct prime factors.

It is a plaindrome in base 7.

It is a nialpdrome in base 10.

It is a junction number, because it is equal to n+sod(n) for n = 8395 and 8404.

It is not an unprimeable number, because it can be changed into a prime (8423) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (5) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 191 + ... + 230.

It is an arithmetic number, because the mean of its divisors is an integer number (1477).

It is an amenable number.

8420 is an abundant number, since it is smaller than the sum of its proper divisors (9304).

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 (8862).

8420 is a wasteful number, since it uses less digits than its factorization.

8420 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 430 (or 428 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 14.

The square root of 8420 is about 91.7605579756. The cubic root of 8420 is about 20.3440476245.

Adding to 8420 its reverse (248), we get a palindrome (8668).

The spelling of 8420 in words is "eight thousand, four hundred twenty".

Divisors: 1 2 4 5 10 20 421 842 1684 2105 4210 8420