128200081 has 4 divisors (see below), whose sum is σ = 128699172. Its totient is φ = 127700992.

The previous prime is 128200021. The next prime is 128200123. The reversal of 128200081 is 180002821.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 124992400 + 3207681 = 11180^2 + 1791^2 .

It is a cyclic number.

It is not a de Polignac number, because 128200081 - 2²¹ = 126102929 is a prime.

It is a super-2 number, since 2×128200081² = 32870521536813122, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (128200001) 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, 249160 + ... + 249673.

It is an arithmetic number, because the mean of its divisors is an integer number (32174793).

Almost surely, 2^128200081 is an apocalyptic number.

It is an amenable number.

128200081 is a deficient number, since it is larger than the sum of its proper divisors (499091).

128200081 is an equidigital number, since it uses as much as digits as its factorization.

128200081 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 499090.

The product of its (nonzero) digits is 256, while the sum is 22.

The square root of 128200081 is about 11322.5474607087. The cubic root of 128200081 is about 504.2308731136.

The spelling of 128200081 in words is "one hundred twenty-eight million, two hundred thousand, eighty-one".