6440443 has 2 divisors, whose sum is σ = 6440444. Its totient is φ = 6440442.

The previous prime is 6440431. The next prime is 6440453. The reversal of 6440443 is 3440446.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 6440443 - 2¹⁷ = 6309371 is a prime.

6440443 is a lucky number.

It is not a weakly prime, because it can be changed into another prime (6440453) 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, 3220221 + 3220222.

It is an arithmetic number, because the mean of its divisors is an integer number (3220222).

Almost surely, 2^6440443 is an apocalyptic number.

6440443 is a deficient number, since it is larger than the sum of its proper divisors (1).

6440443 is an equidigital number, since it uses as much as digits as its factorization.

6440443 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 4608, while the sum is 25.

The square root of 6440443 is about 2537.8027898164. The cubic root of 6440443 is about 186.0538153142.

Adding to 6440443 its reverse (3440446), we get a palindrome (9880889).

The spelling of 6440443 in words is "six million, four hundred forty thousand, four hundred forty-three".