4045 has 4 divisors (see below), whose sum is σ = 4860. Its totient is φ = 3232.

The previous prime is 4027. The next prime is 4049. The reversal of 4045 is 5404.

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 2601 + 1444 = 51^2 + 38^2 .

It is a cyclic number.

It is not a de Polignac number, because 4045 - 2⁵ = 4013 is a prime.

4045 is a modest number, since divided by 45 gives 40 as remainder.

4045 is a lucky number.

It is a plaindrome in base 14.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (4049) 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, 400 + ... + 409.

It is an arithmetic number, because the mean of its divisors is an integer number (1215).

2⁴⁰⁴⁵ is an apocalyptic number.

It is an amenable number.

4045 is a deficient number, since it is larger than the sum of its proper divisors (815).

4045 is an equidigital number, since it uses as much as digits as its factorization.

4045 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 814.

The product of its (nonzero) digits is 80, while the sum is 13.

The square root of 4045 is about 63.6003144646. The cubic root of 4045 is about 15.9333162157.

Adding to 4045 its reverse (5404), we get a palindrome (9449).

The spelling of 4045 in words is "four thousand, forty-five".