81116005 has 8 divisors (see below), whose sum is σ = 97420824. Its totient is φ = 64838400.

The previous prime is 81115967. The next prime is 81116041. The reversal of 81116005 is 50061118.

It can be written as a sum of positive squares in 4 ways, for example, as 40742689 + 40373316 = 6383^2 + 6354^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 81116005 - 2¹⁵ = 81083237 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 465 + ... + 12745.

It is an arithmetic number, because the mean of its divisors is an integer number (12177603).

Almost surely, 2^81116005 is an apocalyptic number.

It is an amenable number.

81116005 is a deficient number, since it is larger than the sum of its proper divisors (16304819).

81116005 is a wasteful number, since it uses less digits than its factorization.

81116005 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13607.

The product of its (nonzero) digits is 240, while the sum is 22.

The square root of 81116005 is about 9006.4424164039. The cubic root of 81116005 is about 432.8813258505.

The spelling of 81116005 in words is "eighty-one million, one hundred sixteen thousand, five".