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BaseRepresentation
bin100000111001
32212222
4200321
531410
613425
76065
oct4071
92788
102105
111644
121275
13c5c
14aa5
15955
hex839

2105 has 4 divisors (see below), whose sum is σ = 2532. Its totient is φ = 1680.

The previous prime is 2099. The next prime is 2111. The reversal of 2105 is 5012.

2105 is nontrivially palindromic in base 13.

It is a semiprime because it is the product of two primes.

It is an interprime number because it is at equal distance from previous prime (2099) and next prime (2111).

It can be written as a sum of positive squares in 2 ways, for example, as 256 + 1849 = 16^2 + 43^2 .

It is not a de Polignac number, because 2105 - 24 = 2089 is a prime.

It is an alternating number because its digits alternate between even and odd.

It is a Duffinian number.

2105 is an undulating number in base 13.

It is a Curzon number.

It is a plaindrome in base 9.

It is a nialpdrome in base 14 and base 15.

It is a junction number, because it is equal to n+sod(n) for n = 2092 and 2101.

It is an unprimeable number.

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, 206 + ... + 215.

It is an arithmetic number, because the mean of its divisors is an integer number (633).

22105 is an apocalyptic number.

It is an amenable number.

2105 is a deficient number, since it is larger than the sum of its proper divisors (427).

2105 is an equidigital number, since it uses as much as digits as its factorization.

2105 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 426.

The product of its (nonzero) digits is 10, while the sum is 8.

The square root of 2105 is about 45.8802789878. The cubic root of 2105 is about 12.8159469211.

Adding to 2105 its reverse (5012), we get a palindrome (7117).

It can be divided in two parts, 2 and 105, that multiplied together give a triangular number (210 = T20).

The spelling of 2105 in words is "two thousand, one hundred five".

Divisors: 1 5 421 2105