4105 has 4 divisors (see below), whose sum is σ = 4932.
Its totient is φ = 3280.
The previous prime is 4099. The next prime is 4111. The reversal of 4105 is 5014.
Subtracting from 4105 its sum of digits (10), we obtain a triangular number (4095 = T90).
Adding to 4105 its reverse (5014), we get a palindrome (9119).
Subtracting 4105 from its reverse (5014), we obtain a palindrome (909).
4105 = T38 + T39 + ... +
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 (4099) and next prime (4111).
It can be written as a sum of positive squares in 2 ways, for example, as 1296 + 2809 = 36^2 + 53^2
It is not a de Polignac number, because 4105 - 25 = 4073 is a prime.
It is an alternating number because its digits alternate between even and odd.
It is a Duffinian number.
4105 is a lucky number.
It is a plaindrome in base 15.
It is a junction number, because it is equal to n+sod(n) for n = 4091 and 4100.
It is an unprimeable number.
It is a pernicious number, because its binary representation contains a prime number (3) of ones.
It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 406 + ... + 415.
It is an arithmetic number, because the mean of its divisors is an integer number (1233).
24105 is an apocalyptic number.
It is an amenable number.
4105 is a deficient number, since it is larger than the sum of its proper divisors (827).
4105 is an equidigital number, since it uses as much as digits as its factorization.
4105 is an odious number, because the sum of its binary digits is odd.
The sum of its prime factors is 826.
The product of its (nonzero) digits is 20, while the sum is 10.
The square root of 4105 is about 64.0702739186.
The cubic root of 4105 is about 16.0117101774.
The spelling of 4105 in words is "four thousand, one hundred five".