20567 has 4 divisors (see below), whose sum is σ = 20856. Its totient is φ = 20280.

The previous prime is 20563. The next prime is 20593. The reversal of 20567 is 76502.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 20567 - 2² = 20563 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20563) 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, 53 + ... + 209.

It is an arithmetic number, because the mean of its divisors is an integer number (5214).

2²⁰⁵⁶⁷ is an apocalyptic number.

20567 is a deficient number, since it is larger than the sum of its proper divisors (289).

20567 is a wasteful number, since it uses less digits than its factorization.

20567 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 288.

The product of its (nonzero) digits is 420, while the sum is 20.

The square root of 20567 is about 143.4119939196. The cubic root of 20567 is about 27.3983020597.

It can be divided in two parts, 205 and 67, that added together give a palindrome (272).

The spelling of 20567 in words is "twenty thousand, five hundred sixty-seven".