81385866607 has 2 divisors, whose sum is σ = 81385866608. Its totient is φ = 81385866606.

The previous prime is 81385866593. The next prime is 81385866631. The reversal of 81385866607 is 70666858318.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 81385866607 - 2¹¹ = 81385864559 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (81385866007) 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, 40692933303 + 40692933304.

It is an arithmetic number, because the mean of its divisors is an integer number (40692933304).

Almost surely, 2^81385866607 is an apocalyptic number.

81385866607 is a deficient number, since it is larger than the sum of its proper divisors (1).

81385866607 is an equidigital number, since it uses as much as digits as its factorization.

81385866607 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 11612160, while the sum is 58.

The spelling of 81385866607 in words is "eighty-one billion, three hundred eighty-five million, eight hundred sixty-six thousand, six hundred seven".