21222043 has 2 divisors, whose sum is σ = 21222044. Its totient is φ = 21222042.

The previous prime is 21222041. The next prime is 21222143. The reversal of 21222043 is 34022212.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21222043 - 2¹ = 21222041 is a prime.

Together with 21222041, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (21222041) 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 as a sum of consecutive naturals, namely, 10611021 + 10611022.

It is an arithmetic number, because the mean of its divisors is an integer number (10611022).

Almost surely, 2^21222043 is an apocalyptic number.

21222043 is a deficient number, since it is larger than the sum of its proper divisors (1).

21222043 is an equidigital number, since it uses as much as digits as its factorization.

21222043 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 192, while the sum is 16.

The square root of 21222043 is about 4606.7388682234. The cubic root of 21222043 is about 276.8613911174.

Adding to 21222043 its reverse (34022212), we get a palindrome (55244255).

The spelling of 21222043 in words is "twenty-one million, two hundred twenty-two thousand, forty-three".