2545 has 4 divisors (see below), whose sum is σ = 3060.
Its totient is φ = 2032.
The previous prime is 2543. The next prime is 2549. The reversal of 2545 is 5452.
It is a happy number.
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 1521 + 1024 = 39^2 + 32^2
It is a cyclic number.
It is not a de Polignac number, because 2545 - 21 = 2543 is a prime.
It is an alternating number because its digits alternate between even and odd.
2545 is a modest number, since divided by 45 gives 25 as remainder.
2545 is a lucky number.
It is not an unprimeable number, because it can be changed into a prime (2543) 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 3 ways as a sum of consecutive naturals, for example, 250 + ... + 259.
It is an arithmetic number, because the mean of its divisors is an integer number (765).
22545 is an apocalyptic number.
It is an amenable number.
2545 is a deficient number, since it is larger than the sum of its proper divisors (515).
2545 is an equidigital number, since it uses as much as digits as its factorization.
2545 is an odious number, because the sum of its binary digits is odd.
The sum of its prime factors is 514.
The product of its digits is 200, while the sum is 16.
The square root of 2545 is about 50.4479930225.
The cubic root of 2545 is about 13.6530368444.
Adding to 2545 its reverse (5452), we get a palindrome (7997).
The spelling of 2545 in words is "two thousand, five hundred forty-five".