2564 has 6 divisors (see below), whose sum is σ = 4494.
Its totient is φ = 1280.
The previous prime is 2557. The next prime is 2579. The reversal of 2564 is 4652.
It can be divided in two parts, 256 and 4, that multiplied together give a 10-th power (1024 = 210).
It can be written as a sum of positive squares in only one way, i.e., 2500 + 64 = 50^2 + 8^2
It is a plaindrome in base 9 and base 13.
It is an unprimeable number.
2564 is an untouchable number, because it is not equal to the sum of proper divisors of any number.
It is a pernicious number, because its binary representation contains a prime number (3) of ones.
It is a polite number, since it can be written as a sum of consecutive naturals, namely, 317 + ... + 324.
It is an arithmetic number, because the mean of its divisors is an integer number (749).
22564 is an apocalyptic number.
It is an amenable number.
2564 is a deficient number, since it is larger than the sum of its proper divisors (1930).
2564 is a wasteful number, since it uses less digits than its factorization.
2564 is an odious number, because the sum of its binary digits is odd.
The sum of its prime factors is 645 (or 643 counting only the distinct ones).
The product of its digits is 240, while the sum is 17.
The square root of 2564 is about 50.6359556047.
The cubic root of 2564 is about 13.6869287655.
The spelling of 2564 in words is "two thousand, five hundred sixty-four".