21822505 has 4 divisors (see below), whose sum is σ = 26187012. Its totient is φ = 17458000.

The previous prime is 21822497. The next prime is 21822517. The reversal of 21822505 is 50522812.

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 6953769 + 14868736 = 2637^2 + 3856^2 .

It is not a de Polignac number, because 21822505 - 2³ = 21822497 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 21822505.

It is an unprimeable number.

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, 2182246 + ... + 2182255.

It is an arithmetic number, because the mean of its divisors is an integer number (6546753).

Almost surely, 2^21822505 is an apocalyptic number.

It is an amenable number.

21822505 is a deficient number, since it is larger than the sum of its proper divisors (4364507).

21822505 is an equidigital number, since it uses as much as digits as its factorization.

21822505 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4364506.

The product of its (nonzero) digits is 1600, while the sum is 25.

The square root of 21822505 is about 4671.4564110136. The cubic root of 21822505 is about 279.4483398452.

The spelling of 21822505 in words is "twenty-one million, eight hundred twenty-two thousand, five hundred five".