4221643 has 2 divisors, whose sum is σ = 4221644. Its totient is φ = 4221642.

The previous prime is 4221641. The next prime is 4221649. The reversal of 4221643 is 3461224.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 4221643 - 2¹ = 4221641 is a prime.

Together with 4221641, it forms a pair of twin primes.

It is an Ulam number.

It is not a weakly prime, because it can be changed into another prime (4221641) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2110821 + 2110822.

It is an arithmetic number, because the mean of its divisors is an integer number (2110822).

Almost surely, 2^4221643 is an apocalyptic number.

4221643 is a deficient number, since it is larger than the sum of its proper divisors (1).

4221643 is an equidigital number, since it uses as much as digits as its factorization.

4221643 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1152, while the sum is 22.

The square root of 4221643 is about 2054.6637194441. The cubic root of 4221643 is about 161.6195283029.

Adding to 4221643 its reverse (3461224), we get a palindrome (7682867).

The spelling of 4221643 in words is "four million, two hundred twenty-one thousand, six hundred forty-three".