81008243 has 2 divisors, whose sum is σ = 81008244. Its totient is φ = 81008242.

The previous prime is 81008233. The next prime is 81008273. The reversal of 81008243 is 34280018.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-81008243 is a prime.

It is not a weakly prime, because it can be changed into another prime (81008233) 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, 40504121 + 40504122.

It is an arithmetic number, because the mean of its divisors is an integer number (40504122).

Almost surely, 2^81008243 is an apocalyptic number.

81008243 is a deficient number, since it is larger than the sum of its proper divisors (1).

81008243 is an equidigital number, since it uses as much as digits as its factorization.

81008243 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1536, while the sum is 26.

The square root of 81008243 is about 9000.4579327943. The cubic root of 81008243 is about 432.6895477094.

The spelling of 81008243 in words is "eighty-one million, eight thousand, two hundred forty-three".