22518161 has 4 divisors (see below), whose sum is σ = 22599732. Its totient is φ = 22436592.

The previous prime is 22518137. The next prime is 22518179. The reversal of 22518161 is 16181522.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 3682561 + 18835600 = 1919^2 + 4340^2 .

It is a cyclic number.

It is not a de Polignac number, because 22518161 - 2¹⁴ = 22501777 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 22518161.

It is not an unprimeable number, because it can be changed into a prime (22518191) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 40370 + ... + 40923.

It is an arithmetic number, because the mean of its divisors is an integer number (5649933).

Almost surely, 2^22518161 is an apocalyptic number.

It is an amenable number.

22518161 is a deficient number, since it is larger than the sum of its proper divisors (81571).

22518161 is an equidigital number, since it uses as much as digits as its factorization.

22518161 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 81570.

The product of its digits is 960, while the sum is 26.

The square root of 22518161 is about 4745.3304416026. The cubic root of 22518161 is about 282.3867444832.

Adding to 22518161 its reverse (16181522), we get a palindrome (38699683).

The spelling of 22518161 in words is "twenty-two million, five hundred eighteen thousand, one hundred sixty-one".