21089833 has 2 divisors, whose sum is σ = 21089834. Its totient is φ = 21089832.

The previous prime is 21089819. The next prime is 21089839. The reversal of 21089833 is 33898012.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 19642624 + 1447209 = 4432^2 + 1203^2 .

It is a cyclic number.

It is not a de Polignac number, because 21089833 - 2²¹ = 18992681 is a prime.

It is not a weakly prime, because it can be changed into another prime (21089839) 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 as a sum of consecutive naturals, namely, 10544916 + 10544917.

It is an arithmetic number, because the mean of its divisors is an integer number (10544917).

Almost surely, 2^21089833 is an apocalyptic number.

It is an amenable number.

21089833 is a deficient number, since it is larger than the sum of its proper divisors (1).

21089833 is an equidigital number, since it uses as much as digits as its factorization.

21089833 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 10368, while the sum is 34.

The square root of 21089833 is about 4592.3668189725. The cubic root of 21089833 is about 276.2852587006.

The spelling of 21089833 in words is "twenty-one million, eighty-nine thousand, eight hundred thirty-three".