81567071 has 6 divisors (see below), whose sum is σ = 86647680. Its totient is φ = 76768736.

The previous prime is 81567049. The next prime is 81567077. The reversal of 81567071 is 17076518.

It is not a de Polignac number, because 81567071 - 2¹⁰ = 81566047 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81567077) 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 5 ways as a sum of consecutive naturals, for example, 140831 + ... + 141408.

It is an arithmetic number, because the mean of its divisors is an integer number (14441280).

Almost surely, 2^81567071 is an apocalyptic number.

81567071 is a deficient number, since it is larger than the sum of its proper divisors (5080609).

81567071 is a wasteful number, since it uses less digits than its factorization.

81567071 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 282273 (or 282256 counting only the distinct ones).

The product of its (nonzero) digits is 11760, while the sum is 35.

The square root of 81567071 is about 9031.4489978076. The cubic root of 81567071 is about 433.6822250684.

The spelling of 81567071 in words is "eighty-one million, five hundred sixty-seven thousand, seventy-one".