81445159 has 2 divisors, whose sum is σ = 81445160. Its totient is φ = 81445158.

The previous prime is 81445141. The next prime is 81445171. The reversal of 81445159 is 95154418.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 81445159 - 2⁹ = 81444647 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (81445109) 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, 40722579 + 40722580.

It is an arithmetic number, because the mean of its divisors is an integer number (40722580).

Almost surely, 2^81445159 is an apocalyptic number.

81445159 is a deficient number, since it is larger than the sum of its proper divisors (1).

81445159 is an equidigital number, since it uses as much as digits as its factorization.

81445159 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 28800, while the sum is 37.

The square root of 81445159 is about 9024.6971694346. The cubic root of 81445159 is about 433.4660535610.

The spelling of 81445159 in words is "eighty-one million, four hundred forty-five thousand, one hundred fifty-nine".