128381217 has 8 divisors (see below), whose sum is σ = 171623424. Its totient is φ = 85363248.

The previous prime is 128381213. The next prime is 128381249. The reversal of 128381217 is 712183821.

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

It is not a de Polignac number, because 128381217 - 2² = 128381213 is a prime.

It is a Smith number, since the sum of its digits (33) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is not an unprimeable number, because it can be changed into a prime (128381213) 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, 54718 + ... + 57015.

It is an arithmetic number, because the mean of its divisors is an integer number (21452928).

Almost surely, 2^128381217 is an apocalyptic number.

It is an amenable number.

128381217 is a deficient number, since it is larger than the sum of its proper divisors (43242207).

128381217 is a wasteful number, since it uses less digits than its factorization.

128381217 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 112119.

The product of its digits is 5376, while the sum is 33.

The square root of 128381217 is about 11330.5435438906. The cubic root of 128381217 is about 504.4682400495.

The spelling of 128381217 in words is "one hundred twenty-eight million, three hundred eighty-one thousand, two hundred seventeen".