81728576 has 28 divisors (see below), whose sum is σ = 170718480. Its totient is φ = 38712960.

The previous prime is 81728567. The next prime is 81728579. The reversal of 81728576 is 67582718.

It is not an unprimeable number, because it can be changed into a prime (81728579) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 32390 + ... + 34821.

Almost surely, 2^81728576 is an apocalyptic number.

It is an amenable number.

81728576 is an abundant number, since it is smaller than the sum of its proper divisors (88989904).

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

81728576 is a wasteful number, since it uses less digits than its factorization.

81728576 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 67242 (or 67232 counting only the distinct ones).

The product of its digits is 188160, while the sum is 44.

The square root of 81728576 is about 9040.3858324742. The cubic root of 81728576 is about 433.9682705254.

The spelling of 81728576 in words is "eighty-one million, seven hundred twenty-eight thousand, five hundred seventy-six".