128520805 has 8 divisors (see below), whose sum is σ = 176257152. Its totient is φ = 88128528.

The previous prime is 128520797. The next prime is 128520809. The reversal of 128520805 is 508025821.

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

It is a cyclic number.

It is not a de Polignac number, because 128520805 - 2³ = 128520797 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (128520809) 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 7 ways as a sum of consecutive naturals, for example, 1835977 + ... + 1836046.

It is an arithmetic number, because the mean of its divisors is an integer number (22032144).

Almost surely, 2^128520805 is an apocalyptic number.

It is an amenable number.

128520805 is a deficient number, since it is larger than the sum of its proper divisors (47736347).

128520805 is an equidigital number, since it uses as much as digits as its factorization.

128520805 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3672035.

The product of its (nonzero) digits is 6400, while the sum is 31.

The square root of 128520805 is about 11336.7016808241. The cubic root of 128520805 is about 504.6510087550.

The spelling of 128520805 in words is "one hundred twenty-eight million, five hundred twenty thousand, eight hundred five".