22561 has 8 divisors (see below), whose sum is σ = 28224. Its totient is φ = 17520.

The previous prime is 22549. The next prime is 22567. The reversal of 22561 is 16522.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 22561 - 2⁷ = 22433 is a prime.

It is not an unprimeable number, because it can be changed into a prime (22567) 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 in 7 ways as a sum of consecutive naturals, for example, 70 + ... + 223.

It is an arithmetic number, because the mean of its divisors is an integer number (3528).

2²²⁵⁶¹ is an apocalyptic number.

It is an amenable number.

22561 is a deficient number, since it is larger than the sum of its proper divisors (5663).

22561 is a wasteful number, since it uses less digits than its factorization.

22561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 311.

The product of its digits is 120, while the sum is 16.

The square root of 22561 is about 150.2031957050. The cubic root of 22561 is about 28.2565703777.

The spelling of 22561 in words is "twenty-two thousand, five hundred sixty-one".