128211839 has 4 divisors (see below), whose sum is σ = 146527824. Its totient is φ = 109895856.

The previous prime is 128211827. The next prime is 128211851. The reversal of 128211839 is 938112821.

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

It is an interprime number because it is at equal distance from previous prime (128211827) and next prime (128211851).

It is not a de Polignac number, because 128211839 - 2⁸ = 128211583 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 128211799 and 128211808.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (128211869) 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, 9157982 + ... + 9157995.

It is an arithmetic number, because the mean of its divisors is an integer number (36631956).

Almost surely, 2^128211839 is an apocalyptic number.

128211839 is a deficient number, since it is larger than the sum of its proper divisors (18315985).

128211839 is an equidigital number, since it uses as much as digits as its factorization.

128211839 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18315984.

The product of its digits is 6912, while the sum is 35.

The square root of 128211839 is about 11323.0666782458. The cubic root of 128211839 is about 504.2462879904.

The spelling of 128211839 in words is "one hundred twenty-eight million, two hundred eleven thousand, eight hundred thirty-nine".