81373560571567 has 4 divisors (see below), whose sum is σ = 88771156987176. Its totient is φ = 73975964155960.

The previous prime is 81373560571549. The next prime is 81373560571571. The reversal of 81373560571567 is 76517506537318.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 81373560571567 - 2¹⁹ = 81373560047279 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 81373560571499 and 81373560571508.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81373560571517) 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 3 ways as a sum of consecutive naturals, for example, 3698798207788 + ... + 3698798207809.

It is an arithmetic number, because the mean of its divisors is an integer number (22192789246794).

Almost surely, 2^{81373560571567} is an apocalyptic number.

81373560571567 is a deficient number, since it is larger than the sum of its proper divisors (7397596415609).

81373560571567 is a wasteful number, since it uses less digits than its factorization.

81373560571567 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7397596415608.

The product of its (nonzero) digits is 111132000, while the sum is 64.

The spelling of 81373560571567 in words is "eighty-one trillion, three hundred seventy-three billion, five hundred sixty million, five hundred seventy-one thousand, five hundred sixty-seven".