81344249243 has 2 divisors, whose sum is σ = 81344249244. Its totient is φ = 81344249242.

The previous prime is 81344249237. The next prime is 81344249317. The reversal of 81344249243 is 34294244318.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 81344249243 - 2²⁰ = 81343200667 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 81344249194 and 81344249203.

It is not a weakly prime, because it can be changed into another prime (81344245243) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40672124621 + 40672124622.

It is an arithmetic number, because the mean of its divisors is an integer number (40672124622).

Almost surely, 2^81344249243 is an apocalyptic number.

81344249243 is a deficient number, since it is larger than the sum of its proper divisors (1).

81344249243 is an equidigital number, since it uses as much as digits as its factorization.

81344249243 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 663552, while the sum is 44.

The spelling of 81344249243 in words is "eighty-one billion, three hundred forty-four million, two hundred forty-nine thousand, two hundred forty-three".