81065136 has 20 divisors (see below), whose sum is σ = 209418392. Its totient is φ = 27021696.

The previous prime is 81065123. The next prime is 81065137. The reversal of 81065136 is 63156018.

It is not an unprimeable number, because it can be changed into a prime (81065137) by changing a digit.

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 3 ways as a sum of consecutive naturals, for example, 844381 + ... + 844476.

Almost surely, 2^81065136 is an apocalyptic number.

It is an amenable number.

81065136 is an abundant number, since it is smaller than the sum of its proper divisors (128353256).

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

81065136 is a wasteful number, since it uses less digits than its factorization.

81065136 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1688868 (or 1688862 counting only the distinct ones).

The product of its (nonzero) digits is 4320, while the sum is 30.

The square root of 81065136 is about 9003.6179394730. The cubic root of 81065136 is about 432.7908182503.

The spelling of 81065136 in words is "eighty-one million, sixty-five thousand, one hundred thirty-six".