128197789 has 4 divisors (see below), whose sum is σ = 128221056. Its totient is φ = 128174524.

The previous prime is 128197763. The next prime is 128197801. The reversal of 128197789 is 987791821.

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 128197789 - 2⁵ = 128197757 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 (128197739) 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, 1812 + ... + 16114.

It is an arithmetic number, because the mean of its divisors is an integer number (32055264).

Almost surely, 2^128197789 is an apocalyptic number.

It is an amenable number.

128197789 is a deficient number, since it is larger than the sum of its proper divisors (23267).

128197789 is an equidigital number, since it uses as much as digits as its factorization.

128197789 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 23266.

The product of its digits is 508032, while the sum is 52.

The square root of 128197789 is about 11322.4462462844. The cubic root of 128197789 is about 504.2278681648.

The spelling of 128197789 in words is "one hundred twenty-eight million, one hundred ninety-seven thousand, seven hundred eighty-nine".