81385867 has 2 divisors, whose sum is σ = 81385868. Its totient is φ = 81385866.

The previous prime is 81385859. The next prime is 81385921. The reversal of 81385867 is 76858318.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 81385867 - 2³ = 81385859 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (81385807) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40692933 + 40692934.

It is an arithmetic number, because the mean of its divisors is an integer number (40692934).

Almost surely, 2^81385867 is an apocalyptic number.

81385867 is a deficient number, since it is larger than the sum of its proper divisors (1).

81385867 is an equidigital number, since it uses as much as digits as its factorization.

81385867 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 322560, while the sum is 46.

The square root of 81385867 is about 9021.4115857775. The cubic root of 81385867 is about 433.3608403972.

The spelling of 81385867 in words is "eighty-one million, three hundred eighty-five thousand, eight hundred sixty-seven".