21322225 has 6 divisors (see below), whose sum is σ = 26439590. Its totient is φ = 17057760.

The previous prime is 21322207. The next prime is 21322229. The reversal of 21322225 is 52222312.

It can be written as a sum of positive squares in 3 ways, for example, as 226576 + 21095649 = 476^2 + 4593^2 .

It is not a de Polignac number, because 21322225 - 2¹⁷ = 21191153 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21322229) 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 5 ways as a sum of consecutive naturals, for example, 426420 + ... + 426469.

Almost surely, 2^21322225 is an apocalyptic number.

21322225 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21322225 is a deficient number, since it is larger than the sum of its proper divisors (5117365).

21322225 is an equidigital number, since it uses as much as digits as its factorization.

21322225 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 852899 (or 852894 counting only the distinct ones).

The product of its digits is 480, while the sum is 19.

The square root of 21322225 is about 4617.5994845807. The cubic root of 21322225 is about 277.2963633317.

Adding to 21322225 its reverse (52222312), we get a palindrome (73544537).

The spelling of 21322225 in words is "twenty-one million, three hundred twenty-two thousand, two hundred twenty-five".