81336909 has 8 divisors (see below), whose sum is σ = 112188960. Its totient is φ = 52354736.

The previous prime is 81336889. The next prime is 81336911. The reversal of 81336909 is 90963318.

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 81336909 - 2¹¹ = 81334861 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81336979) 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, 467367 + ... + 467540.

It is an arithmetic number, because the mean of its divisors is an integer number (14023620).

Almost surely, 2^81336909 is an apocalyptic number.

It is an amenable number.

81336909 is a deficient number, since it is larger than the sum of its proper divisors (30852051).

81336909 is a wasteful number, since it uses less digits than its factorization.

81336909 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 934939.

The product of its (nonzero) digits is 34992, while the sum is 39.

The square root of 81336909 is about 9018.6977441314. The cubic root of 81336909 is about 433.2739263071.

The spelling of 81336909 in words is "eighty-one million, three hundred thirty-six thousand, nine hundred nine".