128017557509 has 4 divisors (see below), whose sum is σ = 128141726880. Its totient is φ = 127893388140.

The previous prime is 128017557461. The next prime is 128017557511. The reversal of 128017557509 is 905755710821.

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 128017557509 - 2²⁴ = 128000780293 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 (128017557529) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 62083139 + ... + 62085200.

It is an arithmetic number, because the mean of its divisors is an integer number (32035431720).

Almost surely, 2^128017557509 is an apocalyptic number.

It is an amenable number.

128017557509 is a deficient number, since it is larger than the sum of its proper divisors (124169371).

128017557509 is a wasteful number, since it uses less digits than its factorization.

128017557509 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 124169370.

The product of its (nonzero) digits is 882000, while the sum is 50.

The spelling of 128017557509 in words is "one hundred twenty-eight billion, seventeen million, five hundred fifty-seven thousand, five hundred nine".