81128066 has 8 divisors (see below), whose sum is σ = 121731660. Its totient is φ = 40550848.

The previous prime is 81128027. The next prime is 81128077. The reversal of 81128066 is 66082118.

It can be written as a sum of positive squares in 2 ways, for example, as 65691025 + 15437041 = 8105^2 + 3929^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is an unprimeable number.

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, 5630 + ... + 13926.

Almost surely, 2^81128066 is an apocalyptic number.

81128066 is a deficient number, since it is larger than the sum of its proper divisors (40603594).

81128066 is a wasteful number, since it uses less digits than its factorization.

81128066 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13188.

The product of its (nonzero) digits is 4608, while the sum is 32.

The square root of 81128066 is about 9007.1119677730. Note that the first 3 decimals coincide. The cubic root of 81128066 is about 432.9027795818.

The spelling of 81128066 in words is "eighty-one million, one hundred twenty-eight thousand, sixty-six".