81040850816 has 16 divisors (see below), whose sum is σ = 161448570240. Its totient is φ = 40520425344.

The previous prime is 81040850747. The next prime is 81040850843. The reversal of 81040850816 is 61805804018.

It is a tau number, because it is divible by the number of its divisors (16).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 316565696 + ... + 316565951.

It is an arithmetic number, because the mean of its divisors is an integer number (10090535640).

Almost surely, 2^81040850816 is an apocalyptic number.

It is an amenable number.

81040850816 is a deficient number, since it is larger than the sum of its proper divisors (80407719424).

81040850816 is an equidigital number, since it uses as much as digits as its factorization.

81040850816 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 633131661 (or 633131649 counting only the distinct ones).

The product of its (nonzero) digits is 61440, while the sum is 41.

The spelling of 81040850816 in words is "eighty-one billion, forty million, eight hundred fifty thousand, eight hundred sixteen".