21443043 has 4 divisors (see below), whose sum is σ = 28590728. Its totient is φ = 14295360.

The previous prime is 21443033. The next prime is 21443047. The reversal of 21443043 is 34034412.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 21443043 - 2¹⁰ = 21442019 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21443047) 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 in 3 ways as a sum of consecutive naturals, for example, 3573838 + ... + 3573843.

It is an arithmetic number, because the mean of its divisors is an integer number (7147682).

Almost surely, 2^21443043 is an apocalyptic number.

21443043 is a deficient number, since it is larger than the sum of its proper divisors (7147685).

21443043 is an equidigital number, since it uses as much as digits as its factorization.

21443043 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7147684.

The product of its (nonzero) digits is 1152, while the sum is 21.

The square root of 21443043 is about 4630.6633434099. The cubic root of 21443043 is about 277.8191247904.

Adding to 21443043 its reverse (34034412), we get a palindrome (55477455).

The spelling of 21443043 in words is "twenty-one million, four hundred forty-three thousand, forty-three".