22191 has 8 divisors (see below), whose sum is σ = 31920. Its totient is φ = 13632.

The previous prime is 22189. The next prime is 22193. The reversal of 22191 is 19122.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (22189) and next prime (22193).

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

It is not a de Polignac number, because 22191 - 2¹ = 22189 is a prime.

It is a plaindrome in base 4 and base 16.

It is a zygodrome in base 4.

It is a self number, because there is not a number n which added to its sum of digits gives 22191.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (22193) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 246 + ... + 323.

It is an arithmetic number, because the mean of its divisors is an integer number (3990).

2²²¹⁹¹ is an apocalyptic number.

22191 is a deficient number, since it is larger than the sum of its proper divisors (9729).

22191 is a wasteful number, since it uses less digits than its factorization.

22191 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 585.

The product of its digits is 36, while the sum is 15.

The square root of 22191 is about 148.9664391734. The cubic root of 22191 is about 28.1012490843.

Subtracting from 22191 its product of digits (36), we obtain a triangular number (22155 = T₂₁₀).

The spelling of 22191 in words is "twenty-two thousand, one hundred ninety-one".