128547839 has 4 divisors (see below), whose sum is σ = 146911824. Its totient is φ = 110183856.

The previous prime is 128547779. The next prime is 128547841. The reversal of 128547839 is 938745821.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 128547839 - 2²⁰ = 127499263 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 128547793 and 128547802.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (128547899) 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, 9181982 + ... + 9181995.

It is an arithmetic number, because the mean of its divisors is an integer number (36727956).

Almost surely, 2^128547839 is an apocalyptic number.

128547839 is a deficient number, since it is larger than the sum of its proper divisors (18363985).

128547839 is an equidigital number, since it uses as much as digits as its factorization.

128547839 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18363984.

The product of its digits is 483840, while the sum is 47.

The square root of 128547839 is about 11337.8939402342. The cubic root of 128547839 is about 504.6863902611.

The spelling of 128547839 in words is "one hundred twenty-eight million, five hundred forty-seven thousand, eight hundred thirty-nine".