21422143 has 2 divisors, whose sum is σ = 21422144. Its totient is φ = 21422142.

The previous prime is 21422129. The next prime is 21422221. The reversal of 21422143 is 34122412.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21422143 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21422143.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21422743) 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, 10711071 + 10711072.

It is an arithmetic number, because the mean of its divisors is an integer number (10711072).

Almost surely, 2^21422143 is an apocalyptic number.

21422143 is a deficient number, since it is larger than the sum of its proper divisors (1).

21422143 is an equidigital number, since it uses as much as digits as its factorization.

21422143 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 384, while the sum is 19.

The square root of 21422143 is about 4628.4060971354. The cubic root of 21422143 is about 277.7288343220.

Adding to 21422143 its reverse (34122412), we get a palindrome (55544555).

The spelling of 21422143 in words is "twenty-one million, four hundred twenty-two thousand, one hundred forty-three".