128704517 has 4 divisors (see below), whose sum is σ = 129217536. Its totient is φ = 128191500.

The previous prime is 128704507. The next prime is 128704519. The reversal of 128704517 is 715407821.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 128704517 - 2¹⁰ = 128703493 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 (128704519) 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 3 ways as a sum of consecutive naturals, for example, 256133 + ... + 256634.

It is an arithmetic number, because the mean of its divisors is an integer number (32304384).

Almost surely, 2^128704517 is an apocalyptic number.

It is an amenable number.

128704517 is a deficient number, since it is larger than the sum of its proper divisors (513019).

128704517 is an equidigital number, since it uses as much as digits as its factorization.

128704517 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 513018.

The product of its (nonzero) digits is 15680, while the sum is 35.

The square root of 128704517 is about 11344.8013204287. The cubic root of 128704517 is about 504.8913493668.

The spelling of 128704517 in words is "one hundred twenty-eight million, seven hundred four thousand, five hundred seventeen".