55569 has 4 divisors (see below), whose sum is σ = 74096. Its totient is φ = 37044.

The previous prime is 55547. The next prime is 55579. The reversal of 55569 is 96555.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 55569 - 2⁷ = 55441 is a prime.

It is a super-2 number, since 2×55569² = 6175827522, which contains 22 as substring.

It is a D-number.

It is a Duffinian number.

55569 is a lucky number.

It is a plaindrome in base 10.

It is a nialpdrome in base 16.

It is not an unprimeable number, because it can be changed into a prime (55529) 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, 9259 + ... + 9264.

It is an arithmetic number, because the mean of its divisors is an integer number (18524).

2⁵⁵⁵⁶⁹ is an apocalyptic number.

It is an amenable number.

55569 is a deficient number, since it is larger than the sum of its proper divisors (18527).

55569 is a wasteful number, since it uses less digits than its factorization.

55569 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18526.

The product of its digits is 6750, while the sum is 30.

The square root of 55569 is about 235.7307786438. The cubic root of 55569 is about 38.1602191796.

It can be divided in two parts, 5556 and 9, that added together give a triangular number (5565 = T₁₀₅).

The spelling of 55569 in words is "fifty-five thousand, five hundred sixty-nine".