128205317 has 8 divisors (see below), whose sum is σ = 135711840. Its totient is φ = 120904560.

The previous prime is 128205299. The next prime is 128205353. The reversal of 128205317 is 713502821.

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 128205317 - 2⁸ = 128205061 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (29).

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 128205317.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (128205397) 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, 50159 + ... + 52652.

It is an arithmetic number, because the mean of its divisors is an integer number (16963980).

Almost surely, 2^128205317 is an apocalyptic number.

It is an amenable number.

128205317 is a deficient number, since it is larger than the sum of its proper divisors (7506523).

128205317 is a wasteful number, since it uses less digits than its factorization.

128205317 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 102883.

The product of its (nonzero) digits is 3360, while the sum is 29.

The square root of 128205317 is about 11322.7786783987. The cubic root of 128205317 is about 504.2377376878.

The spelling of 128205317 in words is "one hundred twenty-eight million, two hundred five thousand, three hundred seventeen".