81081443 has 2 divisors, whose sum is σ = 81081444. Its totient is φ = 81081442.

The previous prime is 81081433. The next prime is 81081491. The reversal of 81081443 is 34418018.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 81081443 - 2¹⁴ = 81065059 is a prime.

It is not a weakly prime, because it can be changed into another prime (81081433) 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, 40540721 + 40540722.

It is an arithmetic number, because the mean of its divisors is an integer number (40540722).

Almost surely, 2^81081443 is an apocalyptic number.

81081443 is a deficient number, since it is larger than the sum of its proper divisors (1).

81081443 is an equidigital number, since it uses as much as digits as its factorization.

81081443 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 3072, while the sum is 29.

The square root of 81081443 is about 9004.5234743433. The cubic root of 81081443 is about 432.8198362600.

The spelling of 81081443 in words is "eighty-one million, eighty-one thousand, four hundred forty-three".