21828925 has 6 divisors (see below), whose sum is σ = 27067898. Its totient is φ = 17463120.

The previous prime is 21828913. The next prime is 21828931. The reversal of 21828925 is 52982812.

It can be written as a sum of positive squares in 3 ways, for example, as 1425636 + 20403289 = 1194^2 + 4517^2 .

It is not a de Polignac number, because 21828925 - 2⁹ = 21828413 is a prime.

It is a Duffinian number.

It is a congruent number.

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, 436554 + ... + 436603.

Almost surely, 2^21828925 is an apocalyptic number.

21828925 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21828925 is a deficient number, since it is larger than the sum of its proper divisors (5238973).

21828925 is an equidigital number, since it uses as much as digits as its factorization.

21828925 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 873167 (or 873162 counting only the distinct ones).

The product of its digits is 23040, while the sum is 37.

The square root of 21828925 is about 4672.1435123506. The cubic root of 21828925 is about 279.4757409530.

The spelling of 21828925 in words is "twenty-one million, eight hundred twenty-eight thousand, nine hundred twenty-five".