128389393 has 4 divisors (see below), whose sum is σ = 140061168. Its totient is φ = 116717620.

The previous prime is 128389367. The next prime is 128389439. The reversal of 128389393 is 393983821.

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 a de Polignac number, because none of the positive numbers 2^k-128389393 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (128389343) 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, 5835871 + ... + 5835892.

It is an arithmetic number, because the mean of its divisors is an integer number (35015292).

Almost surely, 2^128389393 is an apocalyptic number.

It is an amenable number.

128389393 is a deficient number, since it is larger than the sum of its proper divisors (11671775).

128389393 is a wasteful number, since it uses less digits than its factorization.

128389393 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11671774.

The product of its digits is 279936, while the sum is 46.

The square root of 128389393 is about 11330.9043328412. The cubic root of 128389393 is about 504.4789488974.

The spelling of 128389393 in words is "one hundred twenty-eight million, three hundred eighty-nine thousand, three hundred ninety-three".