65566 has 4 divisors (see below), whose sum is σ = 98352. Its totient is φ = 32782.

The previous prime is 65563. The next prime is 65579. The reversal of 65566 is 66556.

It is a semiprime because it is the product of two primes.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (65563) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (5) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 16390 + ... + 16393.

It is an arithmetic number, because the mean of its divisors is an integer number (24588).

2⁶⁵⁵⁶⁶ is an apocalyptic number.

65566 is a deficient number, since it is larger than the sum of its proper divisors (32786).

65566 is a wasteful number, since it uses less digits than its factorization.

65566 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 32785.

The product of its digits is 5400, while the sum is 28.

The square root of 65566 is about 256.0585870460. The cubic root of 65566 is about 40.3236246164.

Subtracting 65566 from its reverse (66556), we obtain a triangular number (990 = T₄₄).

The spelling of 65566 in words is "sixty-five thousand, five hundred sixty-six".