81041173505 has 8 divisors (see below), whose sum is σ = 97276986600. Its totient is φ = 64814553216.

The previous prime is 81041173471. The next prime is 81041173511. The reversal of 81041173505 is 50537114018.

It can be written as a sum of positive squares in 4 ways, for example, as 1828759696 + 79212413809 = 42764^2 + 281447^2 .

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 81041173505 - 2¹⁶ = 81041107969 is a prime.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2278790 + ... + 2314079.

It is an arithmetic number, because the mean of its divisors is an integer number (12159623325).

Almost surely, 2^81041173505 is an apocalyptic number.

It is an amenable number.

81041173505 is a deficient number, since it is larger than the sum of its proper divisors (16235813095).

81041173505 is a wasteful number, since it uses less digits than its factorization.

81041173505 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4596403.

The product of its (nonzero) digits is 16800, while the sum is 35.

The spelling of 81041173505 in words is "eighty-one billion, forty-one million, one hundred seventy-three thousand, five hundred five".