2205 has 18 divisors (see below), whose sum is σ = 4446. Its totient is φ = 1008.
The previous prime is 2203. The next prime is 2207. The reversal of 2205 is 5022.
2205 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.
It is an interprime number because it is at equal distance from previous prime (2203) and next prime (2207).
It can be written as a sum of positive squares in only one way, i.e., 1764 + 441 = 42^2 + 21^2 .
It is not a de Polignac number, because 2205 - 21 = 2203 is a prime.
It is a Harshad number since it is a multiple of its sum of digits (9).
It is a d-powerful number, because it can be written as 25 + 0 + 211 + 53 .
It is a plaindrome in base 12 and base 16.
It is a nialpdrome in base 7.
It is a congruent number.
It is not an unprimeable number, because it can be changed into a prime (2203) by changing a digit.
It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 312 + ... + 318.
It is an arithmetic number, because the mean of its divisors is an integer number (247).
2205 is the 30-th heptagonal number.
It is an amenable number.
2205 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.
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 (2223).
2205 is a wasteful number, since it uses less digits than its factorization.
2205 is an evil number, because the sum of its binary digits is even.
The sum of its prime factors is 25 (or 15 counting only the distinct ones).
The product of its (nonzero) digits is 20, while the sum is 9.
The square root of 2205 is about 46.9574275275. The cubic root of 2205 is about 13.0157599791.
Multiplying 2205 by its product of nonzero digits (20), we get a square (44100 = 2102).
Adding to 2205 its reverse (5022), we get a palindrome (7227).
It can be divided in two parts, 220 and 5, that added together give a square (225 = 152).
The spelling of 2205 in words is "two thousand, two hundred five".
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