81112439 has 2 divisors, whose sum is σ = 81112440. Its totient is φ = 81112438.

The previous prime is 81112429. The next prime is 81112441. The reversal of 81112439 is 93421118.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 81112439 - 2⁸ = 81112183 is a prime.

Together with 81112441, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (81112429) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40556219 + 40556220.

It is an arithmetic number, because the mean of its divisors is an integer number (40556220).

Almost surely, 2^81112439 is an apocalyptic number.

81112439 is a deficient number, since it is larger than the sum of its proper divisors (1).

81112439 is an equidigital number, since it uses as much as digits as its factorization.

81112439 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1728, while the sum is 29.

The square root of 81112439 is about 9006.2444448283. The cubic root of 81112439 is about 432.8749823534.

The spelling of 81112439 in words is "eighty-one million, one hundred twelve thousand, four hundred thirty-nine".