81075839 has 8 divisors (see below), whose sum is σ = 92448720. Its totient is φ = 70436736.

The previous prime is 81075833. The next prime is 81075857. The reversal of 81075839 is 93857018.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 81075839 - 2⁸ = 81075583 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 81075796 and 81075805.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81075833) 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 in 7 ways as a sum of consecutive naturals, for example, 183209 + ... + 183650.

It is an arithmetic number, because the mean of its divisors is an integer number (11556090).

Almost surely, 2^81075839 is an apocalyptic number.

81075839 is a deficient number, since it is larger than the sum of its proper divisors (11372881).

81075839 is a wasteful number, since it uses less digits than its factorization.

81075839 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 366889.

The product of its (nonzero) digits is 60480, while the sum is 41.

The square root of 81075839 is about 9004.2122920331. The cubic root of 81075839 is about 432.8098644828.

The spelling of 81075839 in words is "eighty-one million, seventy-five thousand, eight hundred thirty-nine".