2745 has 12 divisors (see below), whose sum is σ = 4836.
Its totient is φ = 1440.
The previous prime is 2741. The next prime is 2749. The reversal of 2745 is 5472.
Adding to 2745 its product of digits (280), we get a square (3025 = 552).
It can be divided in two parts, 2 and 745, that added together give a palindrome (747).
It is a happy number.
2745 is nontrivially palindromic in base 14.
It is a Cunningham number, because it is equal to 143+1.
It is an interprime number because it is at equal distance from previous prime (2741) and next prime (2749).
It can be written as a sum of positive squares in 2 ways, for example, as 441 + 2304 = 21^2 + 48^2
It is not a de Polignac number, because 2745 - 22 = 2741 is a prime.
It is a Smith number, since the sum of its digits (18) coincides with the sum of the digits of its prime factors.
It is an alternating number because its digits alternate between even and odd.
It is a nialpdrome in base 15.
It is not an unprimeable number, because it can be changed into a prime (2741) by changing a digit.
It is a pernicious number, because its binary representation contains a prime number (7) of ones.
It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 15 + ... + 75.
It is an arithmetic number, because the mean of its divisors is an integer number (403).
It is an amenable number.
2745 is a deficient number, since it is larger than the sum of its proper divisors (2091).
2745 is a wasteful number, since it uses less digits than its factorization.
2745 is an odious number, because the sum of its binary digits is odd.
The sum of its prime factors is 72 (or 69 counting only the distinct ones).
The product of its digits is 280, while the sum is 18.
The square root of 2745 is about 52.3927475897.
The cubic root of 2745 is about 14.0017004737.
The spelling of 2745 in words is "two thousand, seven hundred forty-five".