22261 has 4 divisors (see below), whose sum is σ = 22572. Its totient is φ = 21952.

The previous prime is 22259. The next prime is 22271. The reversal of 22261 is 16222.

22261 = 105² + 106².

It is a happy number.

22261 is nontrivially palindromic in base 5.

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, and also an emirpimes, since its reverse is a distinct semiprime: 16222 = 2 ⋅8111.

It can be written as a sum of positive squares in 2 ways, for example, as 11025 + 11236 = 105^2 + 106^2 .

It is a 3-Lehmer number, since φ(22261) divides (22261-1)³.

It is a cyclic number.

It is not a de Polignac number, because 22261 - 2¹ = 22259 is a prime.

It is a Duffinian number.

22261 is an undulating number in base 14.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (22271) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 15 + ... + 211.

It is an arithmetic number, because the mean of its divisors is an integer number (5643).

2²²²⁶¹ is an apocalyptic number.

22261 is the 106-th centered square number.

It is an amenable number.

22261 is a deficient number, since it is larger than the sum of its proper divisors (311).

22261 is a wasteful number, since it uses less digits than its factorization.

22261 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 310.

The product of its digits is 48, while the sum is 13.

The square root of 22261 is about 149.2012064294. The cubic root of 22261 is about 28.1307658960.

Adding to 22261 its reverse (16222), we get a palindrome (38483).

The spelling of 22261 in words is "twenty-two thousand, two hundred sixty-one".