21226225 has 6 divisors (see below), whose sum is σ = 26320550. Its totient is φ = 16980960.

The previous prime is 21226213. The next prime is 21226237. The reversal of 21226225 is 52262212.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (21226213) and next prime (21226237).

It can be written as a sum of positive squares in 3 ways, for example, as 350464 + 20875761 = 592^2 + 4569^2 .

It is not a de Polignac number, because 21226225 - 2⁵ = 21226193 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21226196 and 21226205.

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 5 ways as a sum of consecutive naturals, for example, 424500 + ... + 424549.

Almost surely, 2^21226225 is an apocalyptic number.

21226225 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21226225 is a deficient number, since it is larger than the sum of its proper divisors (5094325).

21226225 is an equidigital number, since it uses as much as digits as its factorization.

21226225 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 849059 (or 849054 counting only the distinct ones).

The product of its digits is 960, while the sum is 22.

The square root of 21226225 is about 4607.1927461308. The cubic root of 21226225 is about 276.8795759562.

Adding to 21226225 its reverse (52262212), we get a palindrome (73488437).

The spelling of 21226225 in words is "twenty-one million, two hundred twenty-six thousand, two hundred twenty-five".