81547836 has 24 divisors (see below), whose sum is σ = 190547280. Its totient is φ = 27144192.

The previous prime is 81547819. The next prime is 81547847. The reversal of 81547836 is 63874518.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4810 + ... + 13646.

It is an arithmetic number, because the mean of its divisors is an integer number (7939470).

Almost surely, 2^81547836 is an apocalyptic number.

It is an amenable number.

81547836 is an abundant number, since it is smaller than the sum of its proper divisors (108999444).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

81547836 is a wasteful number, since it uses less digits than its factorization.

81547836 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9613 (or 9611 counting only the distinct ones).

The product of its digits is 161280, while the sum is 42.

The square root of 81547836 is about 9030.3840449894. The cubic root of 81547836 is about 433.6481323342.

The spelling of 81547836 in words is "eighty-one million, five hundred forty-seven thousand, eight hundred thirty-six".