81784336105 has 16 divisors (see below), whose sum is σ = 100548595728. Its totient is φ = 63822976000.

The previous prime is 81784336097. The next prime is 81784336133. The reversal of 81784336105 is 50163348718.

It can be written as a sum of positive squares in 8 ways, for example, as 21694638681 + 60089697424 = 147291^2 + 245132^2 .

It is not a de Polignac number, because 81784336105 - 2³ = 81784336097 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1769085 + ... + 1814725.

It is an arithmetic number, because the mean of its divisors is an integer number (6284287233).

Almost surely, 2^81784336105 is an apocalyptic number.

It is an amenable number.

81784336105 is a deficient number, since it is larger than the sum of its proper divisors (18764259623).

81784336105 is a wasteful number, since it uses less digits than its factorization.

81784336105 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 54428.

The product of its (nonzero) digits is 483840, while the sum is 46.

The spelling of 81784336105 in words is "eighty-one billion, seven hundred eighty-four million, three hundred thirty-six thousand, one hundred five".