21845233 has 2 divisors, whose sum is σ = 21845234. Its totient is φ = 21845232.

The previous prime is 21845203. The next prime is 21845237. The reversal of 21845233 is 33254812.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 19820304 + 2024929 = 4452^2 + 1423^2 .

It is a cyclic number.

It is not a de Polignac number, because 21845233 - 2¹³ = 21837041 is a prime.

It is not a weakly prime, because it can be changed into another prime (21845237) by changing a digit.

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 as a sum of consecutive naturals, namely, 10922616 + 10922617.

It is an arithmetic number, because the mean of its divisors is an integer number (10922617).

Almost surely, 2^21845233 is an apocalyptic number.

It is an amenable number.

21845233 is a deficient number, since it is larger than the sum of its proper divisors (1).

21845233 is an equidigital number, since it uses as much as digits as its factorization.

21845233 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 5760, while the sum is 28.

The square root of 21845233 is about 4673.8884239999. Note that the first 3 decimals coincide. The cubic root of 21845233 is about 279.5453207402.

It can be divided in two parts, 218 and 45233, that added together give a triangular number (45451 = T₃₀₁).

The spelling of 21845233 in words is "twenty-one million, eight hundred forty-five thousand, two hundred thirty-three".