81085173406 has 16 divisors (see below), whose sum is σ = 127321428384. Its totient is φ = 38655961344.

The previous prime is 81085173391. The next prime is 81085173439. The reversal of 81085173406 is 60437158018.

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, 2801451 + ... + 2830246.

It is an arithmetic number, because the mean of its divisors is an integer number (7957589274).

Almost surely, 2^81085173406 is an apocalyptic number.

81085173406 is a deficient number, since it is larger than the sum of its proper divisors (46236254978).

81085173406 is a wasteful number, since it uses less digits than its factorization.

81085173406 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5632035.

The product of its (nonzero) digits is 161280, while the sum is 43.

The spelling of 81085173406 in words is "eighty-one billion, eighty-five million, one hundred seventy-three thousand, four hundred six".