81835909 has 8 divisors (see below), whose sum is σ = 90417600. Its totient is φ = 73672896.

The previous prime is 81835903. The next prime is 81835913. The reversal of 81835909 is 90953818.

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 81835909 - 2⁷ = 81835781 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81835903) 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 in 7 ways as a sum of consecutive naturals, for example, 104259 + ... + 105040.

It is an arithmetic number, because the mean of its divisors is an integer number (11302200).

Almost surely, 2^81835909 is an apocalyptic number.

It is an amenable number.

81835909 is a deficient number, since it is larger than the sum of its proper divisors (8581691).

81835909 is a wasteful number, since it uses less digits than its factorization.

81835909 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 209339.

The product of its (nonzero) digits is 77760, while the sum is 43.

The square root of 81835909 is about 9046.3201911053. The cubic root of 81835909 is about 434.1581622497.

The spelling of 81835909 in words is "eighty-one million, eight hundred thirty-five thousand, nine hundred nine".