128939443 has 4 divisors (see below), whose sum is σ = 128965320. Its totient is φ = 128913568.

The previous prime is 128939431. The next prime is 128939467. The reversal of 128939443 is 344939821.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 344939821 = 31 ⋅11127091.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-128939443 is a prime.

It is a super-2 number, since 2×128939443² = 33250759922300498, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 128939443.

It is not an unprimeable number, because it can be changed into a prime (128939143) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2833 + ... + 16306.

It is an arithmetic number, because the mean of its divisors is an integer number (32241330).

Almost surely, 2^128939443 is an apocalyptic number.

128939443 is a deficient number, since it is larger than the sum of its proper divisors (25877).

128939443 is an equidigital number, since it uses as much as digits as its factorization.

128939443 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 25876.

The product of its digits is 186624, while the sum is 43.

The square root of 128939443 is about 11355.1505053874. The cubic root of 128939443 is about 505.1983575250.

The spelling of 128939443 in words is "one hundred twenty-eight million, nine hundred thirty-nine thousand, four hundred forty-three".