81145028 has 6 divisors (see below), whose sum is σ = 142003806. Its totient is φ = 40572512.

The previous prime is 81144997. The next prime is 81145039. The reversal of 81145028 is 82054118.

It can be written as a sum of positive squares in only one way, i.e., 62758084 + 18386944 = 7922^2 + 4288^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10143125 + ... + 10143132.

It is an arithmetic number, because the mean of its divisors is an integer number (23667301).

Almost surely, 2^81145028 is an apocalyptic number.

It is an amenable number.

81145028 is a deficient number, since it is larger than the sum of its proper divisors (60858778).

81145028 is a wasteful number, since it uses less digits than its factorization.

81145028 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20286261 (or 20286259 counting only the distinct ones).

The product of its (nonzero) digits is 2560, while the sum is 29.

The square root of 81145028 is about 9008.0535078340. The cubic root of 81145028 is about 432.9329474617.

The spelling of 81145028 in words is "eighty-one million, one hundred forty-five thousand, twenty-eight".