128530709 has 4 divisors (see below), whose sum is σ = 130157760. Its totient is φ = 126903660.

The previous prime is 128530679. The next prime is 128530751. The reversal of 128530709 is 907035821.

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 128530709 - 2¹⁶ = 128465173 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 (128530799) 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, 813407 + ... + 813564.

It is an arithmetic number, because the mean of its divisors is an integer number (32539440).

Almost surely, 2^128530709 is an apocalyptic number.

It is an amenable number.

128530709 is a deficient number, since it is larger than the sum of its proper divisors (1627051).

128530709 is an equidigital number, since it uses as much as digits as its factorization.

128530709 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1627050.

The product of its (nonzero) digits is 15120, while the sum is 35.

The square root of 128530709 is about 11337.1384837621. The cubic root of 128530709 is about 504.6639714688.

The spelling of 128530709 in words is "one hundred twenty-eight million, five hundred thirty thousand, seven hundred nine".