81343709 has 8 divisors (see below), whose sum is σ = 84981312. Its totient is φ = 77714560.

The previous prime is 81343697. The next prime is 81343733. The reversal of 81343709 is 90734318.

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-81343709 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 (81343309) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 25229 + ... + 28269.

It is an arithmetic number, because the mean of its divisors is an integer number (10622664).

Almost surely, 2^81343709 is an apocalyptic number.

It is an amenable number.

81343709 is a deficient number, since it is larger than the sum of its proper divisors (3637603).

81343709 is a wasteful number, since it uses less digits than its factorization.

81343709 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4227.

The product of its (nonzero) digits is 18144, while the sum is 35.

The square root of 81343709 is about 9019.0747308136. The cubic root of 81343709 is about 433.2860002869.

The spelling of 81343709 in words is "eighty-one million, three hundred forty-three thousand, seven hundred nine".