81365759 has 8 divisors (see below), whose sum is σ = 83063232. Its totient is φ = 79674400.

The previous prime is 81365749. The next prime is 81365773. The reversal of 81365759 is 95756318.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-81365759 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81365719) 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, 33434 + ... + 35784.

It is an arithmetic number, because the mean of its divisors is an integer number (10382904).

Almost surely, 2^81365759 is an apocalyptic number.

81365759 is a deficient number, since it is larger than the sum of its proper divisors (1697473).

81365759 is a wasteful number, since it uses less digits than its factorization.

81365759 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3057.

The product of its digits is 226800, while the sum is 44.

The square root of 81365759 is about 9020.2970571927. The cubic root of 81365759 is about 433.3251473141.

The spelling of 81365759 in words is "eighty-one million, three hundred sixty-five thousand, seven hundred fifty-nine".