21033189 has 20 divisors (see below), whose sum is σ = 31755724. Its totient is φ = 13872384.

The previous prime is 21033169. The next prime is 21033193. The reversal of 21033189 is 98133012.

It can be written as a sum of positive squares in 2 ways, for example, as 3744225 + 17288964 = 1935^2 + 4158^2 .

It is not a de Polignac number, because 21033189 - 2⁸ = 21032933 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21033119) 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 19 ways as a sum of consecutive naturals, for example, 6519 + ... + 9195.

Almost surely, 2^21033189 is an apocalyptic number.

It is an amenable number.

21033189 is a deficient number, since it is larger than the sum of its proper divisors (10722535).

21033189 is an equidigital number, since it uses as much as digits as its factorization.

21033189 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2786 (or 2777 counting only the distinct ones).

The product of its (nonzero) digits is 1296, while the sum is 27.

The square root of 21033189 is about 4586.1954820962. The cubic root of 21033189 is about 276.0376838905.

The spelling of 21033189 in words is "twenty-one million, thirty-three thousand, one hundred eighty-nine".