128509717605 has 8 divisors (see below), whose sum is σ = 205615548192. Its totient is φ = 68538516048.

The previous prime is 128509717597. The next prime is 128509717619. The reversal of 128509717605 is 506717905821.

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

It is not a de Polignac number, because 128509717605 - 2³ = 128509717597 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4283657239 + ... + 4283657268.

It is an arithmetic number, because the mean of its divisors is an integer number (25701943524).

Almost surely, 2^128509717605 is an apocalyptic number.

128509717605 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

128509717605 is a deficient number, since it is larger than the sum of its proper divisors (77105830587).

128509717605 is an equidigital number, since it uses as much as digits as its factorization.

128509717605 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8567314515.

The product of its (nonzero) digits is 1058400, while the sum is 51.

The spelling of 128509717605 in words is "one hundred twenty-eight billion, five hundred nine million, seven hundred seventeen thousand, six hundred five".