81219119065 has 16 divisors (see below), whose sum is σ = 111392650368. Its totient is φ = 55689895296.

The previous prime is 81219119057. The next prime is 81219119071. The reversal of 81219119065 is 56091191218.

It is not a de Polignac number, because 81219119065 - 2³ = 81219119057 is a prime.

It is a Duffinian 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 in 15 ways as a sum of consecutive naturals, for example, 658749 + ... + 772261.

It is an arithmetic number, because the mean of its divisors is an integer number (6962040648).

Almost surely, 2^81219119065 is an apocalyptic number.

It is an amenable number.

81219119065 is a deficient number, since it is larger than the sum of its proper divisors (30173531303).

81219119065 is a wasteful number, since it uses less digits than its factorization.

81219119065 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 133968.

The product of its (nonzero) digits is 38880, while the sum is 43.

The spelling of 81219119065 in words is "eighty-one billion, two hundred nineteen million, one hundred nineteen thousand, sixty-five".