81569134238905 has 16 divisors (see below), whose sum is σ = 98526087414144. Its totient is φ = 64826902990080.

The previous prime is 81569134238887. The next prime is 81569134238971. The reversal of 81569134238905 is 50983243196518.

It is not a de Polignac number, because 81569134238905 - 2⁷ = 81569134238777 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 19770544 + ... + 23537473.

It is an arithmetic number, because the mean of its divisors is an integer number (6157880463384).

Almost surely, 2^{81569134238905} is an apocalyptic number.

It is an amenable number.

81569134238905 is a deficient number, since it is larger than the sum of its proper divisors (16956953175239).

81569134238905 is a wasteful number, since it uses less digits than its factorization.

81569134238905 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 43310496.

The product of its (nonzero) digits is 55987200, while the sum is 64.

The spelling of 81569134238905 in words is "eighty-one trillion, five hundred sixty-nine billion, one hundred thirty-four million, two hundred thirty-eight thousand, nine hundred five".