81224443 has 2 divisors, whose sum is σ = 81224444. Its totient is φ = 81224442.

The previous prime is 81224441. The next prime is 81224531. The reversal of 81224443 is 34442218.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 81224443 - 2¹ = 81224441 is a prime.

Together with 81224441, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (81224441) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40612221 + 40612222.

It is an arithmetic number, because the mean of its divisors is an integer number (40612222).

Almost surely, 2^81224443 is an apocalyptic number.

81224443 is a deficient number, since it is larger than the sum of its proper divisors (1).

81224443 is an equidigital number, since it uses as much as digits as its factorization.

81224443 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 6144, while the sum is 28.

The square root of 81224443 is about 9012.4604298715. The cubic root of 81224443 is about 433.0741356563.

The spelling of 81224443 in words is "eighty-one million, two hundred twenty-four thousand, four hundred forty-three".