21828235 has 16 divisors (see below), whose sum is σ = 30774240. Its totient is φ = 14653440.

The previous prime is 21828227. The next prime is 21828239. The reversal of 21828235 is 53282812.

It is not a de Polignac number, because 21828235 - 2³ = 21828227 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21828197 and 21828206.

It is not an unprimeable number, because it can be changed into a prime (21828239) 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 15 ways as a sum of consecutive naturals, for example, 14550 + ... + 15979.

It is an arithmetic number, because the mean of its divisors is an integer number (1923390).

Almost surely, 2^21828235 is an apocalyptic number.

21828235 is a deficient number, since it is larger than the sum of its proper divisors (8946005).

21828235 is a wasteful number, since it uses less digits than its factorization.

21828235 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 30558.

The product of its digits is 7680, while the sum is 31.

The square root of 21828235 is about 4672.0696698572. The cubic root of 21828235 is about 279.4727962318.

The spelling of 21828235 in words is "twenty-one million, eight hundred twenty-eight thousand, two hundred thirty-five".