21230443 has 16 divisors (see below), whose sum is σ = 23833600. Its totient is φ = 18779040.

The previous prime is 21230431. The next prime is 21230459. The reversal of 21230443 is 34403212.

It is a cyclic number.

It is not a de Polignac number, because 21230443 - 2¹³ = 21222251 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21230443.

It is not an unprimeable number, because it can be changed into a prime (21230483) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 55828 + ... + 56206.

It is an arithmetic number, because the mean of its divisors is an integer number (1489600).

Almost surely, 2^21230443 is an apocalyptic number.

21230443 is a deficient number, since it is larger than the sum of its proper divisors (2603157).

21230443 is a wasteful number, since it uses less digits than its factorization.

21230443 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 562.

The product of its (nonzero) digits is 576, while the sum is 19.

The square root of 21230443 is about 4607.6504858767. The cubic root of 21230443 is about 276.8979149166.

Adding to 21230443 its reverse (34403212), we get a palindrome (55633655).

The spelling of 21230443 in words is "twenty-one million, two hundred thirty thousand, four hundred forty-three".