22105661 has 4 divisors (see below), whose sum is σ = 23406012. Its totient is φ = 20805312.

The previous prime is 22105649. The next prime is 22105679. The reversal of 22105661 is 16650122.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 16650122 = 2 ⋅8325061.

It can be written as a sum of positive squares in 2 ways, for example, as 18438436 + 3667225 = 4294^2 + 1915^2 .

It is a cyclic number.

It is not a de Polignac number, because 22105661 - 2⁶ = 22105597 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 (22105631) 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, 650150 + ... + 650183.

It is an arithmetic number, because the mean of its divisors is an integer number (5851503).

Almost surely, 2^22105661 is an apocalyptic number.

It is an amenable number.

22105661 is a deficient number, since it is larger than the sum of its proper divisors (1300351).

22105661 is a wasteful number, since it uses less digits than its factorization.

22105661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1300350.

The product of its (nonzero) digits is 720, while the sum is 23.

The square root of 22105661 is about 4701.6657686399. The cubic root of 22105661 is about 280.6518020938.

Adding to 22105661 its reverse (16650122), we get a palindrome (38755783).

The spelling of 22105661 in words is "twenty-two million, one hundred five thousand, six hundred sixty-one".