4145 has 4 divisors (see below), whose sum is σ = 4980. Its totient is φ = 3312.

The previous prime is 4139. The next prime is 4153. The reversal of 4145 is 5414.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 5414 = 2 ⋅2707.

It can be written as a sum of positive squares in 2 ways, for example, as 1936 + 2209 = 44^2 + 47^2 .

It is a cyclic number.

It is not a de Polignac number, because 4145 - 2⁴ = 4129 is a prime.

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

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 410 + ... + 419.

It is an arithmetic number, because the mean of its divisors is an integer number (1245).

2⁴¹⁴⁵ is an apocalyptic number.

It is an amenable number.

4145 is a deficient number, since it is larger than the sum of its proper divisors (835).

4145 is an equidigital number, since it uses as much as digits as its factorization.

4145 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 834.

The product of its digits is 80, while the sum is 14.

The square root of 4145 is about 64.3816744113. The cubic root of 4145 is about 16.0635493417.

Adding to 4145 its product of digits (80), we get a square (4225 = 65²).

Adding to 4145 its reverse (5414), we get a palindrome (9559).

The spelling of 4145 in words is "four thousand, one hundred forty-five".