81086806405 has 16 divisors (see below), whose sum is σ = 106960315968. Its totient is φ = 58522048000.

The previous prime is 81086806403. The next prime is 81086806439. The reversal of 81086806405 is 50460868018.

It is not a de Polignac number, because 81086806405 - 2¹ = 81086806403 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81086806403) by changing a digit.

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 15 ways as a sum of consecutive naturals, for example, 5619916 + ... + 5634325.

It is an arithmetic number, because the mean of its divisors is an integer number (6685019748).

Almost surely, 2^81086806405 is an apocalyptic number.

It is an amenable number.

81086806405 is a deficient number, since it is larger than the sum of its proper divisors (25873509563).

81086806405 is a wasteful number, since it uses less digits than its factorization.

81086806405 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11254388.

The product of its (nonzero) digits is 368640, while the sum is 46.

The spelling of 81086806405 in words is "eighty-one billion, eighty-six million, eight hundred six thousand, four hundred five".