81075328 has 16 divisors (see below), whose sum is σ = 161517510. Its totient is φ = 40537600.

The previous prime is 81075311. The next prime is 81075343. The reversal of 81075328 is 82357018.

It can be written as a sum of positive squares in only one way, i.e., 80138304 + 937024 = 8952^2 + 968^2 .

It is a tau number, because it is divible by the number of its divisors (16).

It is a junction number, because it is equal to n+sod(n) for n = 81075293 and 81075302.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 316573 + ... + 316828.

Almost surely, 2^81075328 is an apocalyptic number.

It is an amenable number.

81075328 is a deficient number, since it is larger than the sum of its proper divisors (80442182).

81075328 is an equidigital number, since it uses as much as digits as its factorization.

81075328 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 633415 (or 633403 counting only the distinct ones).

The product of its (nonzero) digits is 13440, while the sum is 34.

The square root of 81075328 is about 9004.1839163802. The cubic root of 81075328 is about 432.8089551848.

The spelling of 81075328 in words is "eighty-one million, seventy-five thousand, three hundred twenty-eight".