81394283513 has 2 divisors, whose sum is σ = 81394283514. Its totient is φ = 81394283512.

The previous prime is 81394283497. The next prime is 81394283543. The reversal of 81394283513 is 31538249318.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 76183176169 + 5211107344 = 276013^2 + 72188^2 .

It is a cyclic number.

It is not a de Polignac number, because 81394283513 - 2⁴ = 81394283497 is a prime.

It is not a weakly prime, because it can be changed into another prime (81394283543) 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, 40697141756 + 40697141757.

It is an arithmetic number, because the mean of its divisors is an integer number (40697141757).

Almost surely, 2^81394283513 is an apocalyptic number.

It is an amenable number.

81394283513 is a deficient number, since it is larger than the sum of its proper divisors (1).

81394283513 is an equidigital number, since it uses as much as digits as its factorization.

81394283513 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 622080, while the sum is 47.

The spelling of 81394283513 in words is "eighty-one billion, three hundred ninety-four million, two hundred eighty-three thousand, five hundred thirteen".