21253325 has 6 divisors (see below), whose sum is σ = 26354154. Its totient is φ = 17002640.

The previous prime is 21253319. The next prime is 21253333. The reversal of 21253325 is 52335212.

It can be written as a sum of positive squares in 3 ways, for example, as 7496644 + 13756681 = 2738^2 + 3709^2 .

It is not a de Polignac number, because 21253325 - 2²⁰ = 20204749 is a prime.

It is a Duffinian number.

It is a plaindrome in base 16.

It is a self number, because there is not a number n which added to its sum of digits gives 21253325.

It is a congruent number.

It is an unprimeable number.

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, 425042 + ... + 425091.

It is an arithmetic number, because the mean of its divisors is an integer number (4392359).

Almost surely, 2^21253325 is an apocalyptic number.

21253325 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21253325 is a deficient number, since it is larger than the sum of its proper divisors (5100829).

21253325 is an equidigital number, since it uses as much as digits as its factorization.

21253325 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 850143 (or 850138 counting only the distinct ones).

The product of its digits is 1800, while the sum is 23.

The square root of 21253325 is about 4610.1328614260. The cubic root of 21253325 is about 276.9973586441.

Adding to 21253325 its reverse (52335212), we get a palindrome (73588537).

The spelling of 21253325 in words is "twenty-one million, two hundred fifty-three thousand, three hundred twenty-five".