81843717 has 8 divisors (see below), whose sum is σ = 109239040. Its totient is φ = 54505440.

The previous prime is 81843677. The next prime is 81843719. The reversal of 81843717 is 71734818.

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

It is not a de Polignac number, because 81843717 - 2⁷ = 81843589 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 (81843719) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 10792 + ... + 16737.

It is an arithmetic number, because the mean of its divisors is an integer number (13654880).

Almost surely, 2^81843717 is an apocalyptic number.

It is an amenable number.

81843717 is a deficient number, since it is larger than the sum of its proper divisors (27395323).

81843717 is a wasteful number, since it uses less digits than its factorization.

81843717 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 28523.

The product of its digits is 37632, while the sum is 39.

The square root of 81843717 is about 9046.7517375023. The cubic root of 81843717 is about 434.1719695509.

The spelling of 81843717 in words is "eighty-one million, eight hundred forty-three thousand, seven hundred seventeen".