21826225 has 6 divisors (see below), whose sum is σ = 27064550. Its totient is φ = 17460960.

The previous prime is 21826223. The next prime is 21826237. The reversal of 21826225 is 52262812.

21826225 = 3303² + 3304².

It can be written as a sum of positive squares in 3 ways, for example, as 5049009 + 16777216 = 2247^2 + 4096^2 .

It is not a de Polignac number, because 21826225 - 2¹ = 21826223 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21826193 and 21826202.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21826223) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 436500 + ... + 436549.

Almost surely, 2^21826225 is an apocalyptic number.

21826225 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

21826225 is the 3304-th centered square number.

It is an amenable number.

21826225 is a deficient number, since it is larger than the sum of its proper divisors (5238325).

21826225 is an equidigital number, since it uses as much as digits as its factorization.

21826225 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 873059 (or 873054 counting only the distinct ones).

The product of its digits is 3840, while the sum is 28.

The square root of 21826225 is about 4671.8545568115. The cubic root of 21826225 is about 279.4642177773.

The spelling of 21826225 in words is "twenty-one million, eight hundred twenty-six thousand, two hundred twenty-five".