81743083209 has 12 divisors (see below), whose sum is σ = 118092774852. Its totient is φ = 54486420000.

The previous prime is 81743083207. The next prime is 81743083229. The reversal of 81743083209 is 90238034718.

81743083209 is a `hidden beast` number, since 8 + 1 + 7 + 430 + 8 + 3 + 209 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 41709075984 + 40034007225 = 204228^2 + 200085^2 .

It is not a de Polignac number, because 81743083209 - 2¹ = 81743083207 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (81743083207) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 689442 + ... + 799259.

It is an arithmetic number, because the mean of its divisors is an integer number (9841064571).

Almost surely, 2^81743083209 is an apocalyptic number.

It is an amenable number.

81743083209 is a deficient number, since it is larger than the sum of its proper divisors (36349691643).

81743083209 is a wasteful number, since it uses less digits than its factorization.

81743083209 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1494808 (or 1494805 counting only the distinct ones).

The product of its (nonzero) digits is 290304, while the sum is 45.

The spelling of 81743083209 in words is "eighty-one billion, seven hundred forty-three million, eighty-three thousand, two hundred nine".