2645 has 6 divisors (see below), whose sum is σ = 3318. Its totient is φ = 2024.

The previous prime is 2633. The next prime is 2647. The reversal of 2645 is 5462.

2645 = T₃₀ + T₃₁ + ... + T₃₄.

2645 is nontrivially palindromic in base 14.

2645 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in only one way, i.e., 2116 + 529 = 46^2 + 23^2 .

It is not a de Polignac number, because 2645 - 2⁸ = 2389 is a prime.

It is a magnanimous number.

It is a d-powerful number, because it can be written as 2¹¹ + 4⁴ + 6³ + 5³ .

It is a Duffinian number.

2645 is an undulating number in base 14.

It is a plaindrome in base 9.

It is a nialpdrome in base 4, base 15 and base 16.

It is a zygodrome in base 4.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2647) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 104 + ... + 126.

It is an arithmetic number, because the mean of its divisors is an integer number (553).

It is an amenable number.

2645 is a deficient number, since it is larger than the sum of its proper divisors (673).

2645 is an equidigital number, since it uses as much as digits as its factorization.

2645 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 51 (or 28 counting only the distinct ones).

The product of its digits is 240, while the sum is 17.

The square root of 2645 is about 51.4295634825. The cubic root of 2645 is about 13.8295662393.

Adding to 2645 its sum of digits (17), we get a palindrome (2662).

Subtracting from 2645 its sum of digits (17), we obtain a triangular number (2628 = T₇₂).

The spelling of 2645 in words is "two thousand, six hundred forty-five".