6566 has 12 divisors (see below), whose sum is σ = 11628. Its totient is φ = 2772.

The previous prime is 6563. The next prime is 6569. The reversal of 6566 is 6656.

6566 = 39² + 40² + ... + 42².

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (6563) and next prime (6569).

It is a super-2 number, since 2×6566² = 86224712, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6563) 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 5 ways as a sum of consecutive naturals, for example, 65 + ... + 131.

It is an arithmetic number, because the mean of its divisors is an integer number (969).

2⁶⁵⁶⁶ is an apocalyptic number.

6566 is a deficient number, since it is larger than the sum of its proper divisors (5062).

6566 is a wasteful number, since it uses less digits than its factorization.

6566 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 83 (or 76 counting only the distinct ones).

The product of its digits is 1080, while the sum is 23.

The square root of 6566 is about 81.0308583195. The cubic root of 6566 is about 18.7255087642.

It can be divided in two parts, 65 and 66, that added together give a palindrome (131).

The spelling of 6566 in words is "six thousand, five hundred sixty-six".