128505855 has 8 divisors (see below), whose sum is σ = 205609392. Its totient is φ = 68536448.

The previous prime is 128505841. The next prime is 128505857. The reversal of 128505855 is 558505821.

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 128505855 - 2⁹ = 128505343 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (128505857) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4283514 + ... + 4283543.

It is an arithmetic number, because the mean of its divisors is an integer number (25701174).

Almost surely, 2^128505855 is an apocalyptic number.

128505855 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

128505855 is a deficient number, since it is larger than the sum of its proper divisors (77103537).

128505855 is an equidigital number, since it uses as much as digits as its factorization.

128505855 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8567065.

The product of its (nonzero) digits is 80000, while the sum is 39.

The square root of 128505855 is about 11336.0422987919. The cubic root of 128505855 is about 504.6314403924.

The spelling of 128505855 in words is "one hundred twenty-eight million, five hundred five thousand, eight hundred fifty-five".