21043033 has 4 divisors (see below), whose sum is σ = 22956048. Its totient is φ = 19130020.

The previous prime is 21043027. The next prime is 21043037. The reversal of 21043033 is 33034012.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21043033 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21042998 and 21043016.

It is not an unprimeable number, because it can be changed into a prime (21043037) 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 3 ways as a sum of consecutive naturals, for example, 956491 + ... + 956512.

It is an arithmetic number, because the mean of its divisors is an integer number (5739012).

Almost surely, 2^21043033 is an apocalyptic number.

It is an amenable number.

21043033 is a deficient number, since it is larger than the sum of its proper divisors (1913015).

21043033 is a wasteful number, since it uses less digits than its factorization.

21043033 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1913014.

The product of its (nonzero) digits is 216, while the sum is 16.

The square root of 21043033 is about 4587.2685772690. The cubic root of 21043033 is about 276.0807410980.

Adding to 21043033 its reverse (33034012), we get a palindrome (54077045).

The spelling of 21043033 in words is "twenty-one million, forty-three thousand, thirty-three".