3805 has 4 divisors (see below), whose sum is σ = 4572. Its totient is φ = 3040.

The previous prime is 3803. The next prime is 3821. The reversal of 3805 is 5083.

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

It can be written as a sum of positive squares in 2 ways, for example, as 441 + 3364 = 21^2 + 58^2 .

It is not a de Polignac number, because 3805 - 2¹ = 3803 is a prime.

It is a Duffinian number.

It is a plaindrome in base 14.

It is a nialpdrome in base 16.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 3805.

It is not an unprimeable number, because it can be changed into a prime (3803) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 376 + ... + 385.

It is an arithmetic number, because the mean of its divisors is an integer number (1143).

2³⁸⁰⁵ is an apocalyptic number.

It is an amenable number.

3805 is a deficient number, since it is larger than the sum of its proper divisors (767).

3805 is an equidigital number, since it uses as much as digits as its factorization.

3805 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 766.

The product of its (nonzero) digits is 120, while the sum is 16.

The square root of 3805 is about 61.6846820532. The cubic root of 3805 is about 15.6117487651.

Adding to 3805 its reverse (5083), we get a palindrome (8888).

It can be divided in two parts, 3 and 805, that multiplied together give a triangular number (2415 = T₆₉).

The spelling of 3805 in words is "three thousand, eight hundred five".