128436881 has 2 divisors, whose sum is σ = 128436882.
Its totient is φ = 128436880.
The previous prime is 128436877. The next prime is 128436883. The reversal of 128436881 is 188634821.
It is a strong prime.
It can be written as a sum of positive squares in only one way, i.e., 110586256 + 17850625 = 10516^2 + 4225^2
It is a cyclic number.
It is not a de Polignac number, because 128436881 - 22 = 128436877 is a prime.
It is a super-2 number, since 2×1284368812 = 32992064802016322, which contains 22 as substring.
It is a Sophie Germain prime.
Together with 128436883, it forms a pair of twin primes.
It is a Chen prime.
It is a Curzon number.
It is not a weakly prime, because it can be changed into another prime (128436883) by changing a digit.
It is a polite number, since it can be written as a sum of consecutive naturals, namely, 64218440 + 64218441.
It is an arithmetic number, because the mean of its divisors is an integer number (64218441).
Almost surely, 2128436881 is an apocalyptic number.
It is an amenable number.
128436881 is a deficient number, since it is larger than the sum of its proper divisors (1).
128436881 is an equidigital number, since it uses as much as digits as its factorization.
128436881 is an odious number, because the sum of its binary digits is odd.
The product of its digits is 73728, while the sum is 41.
The square root of 128436881 is about 11332.9996470484.
Note that the first 3 decimals coincide.
The cubic root of 128436881 is about 504.5411392459.
The spelling of 128436881 in words is "one hundred twenty-eight million, four hundred thirty-six thousand, eight hundred eighty-one".