128642239 has 6 divisors (see below), whose sum is σ = 141400280. Its totient is φ = 116947380.

The previous prime is 128642221. The next prime is 128642249. The reversal of 128642239 is 932246821.

It is a happy number.

It is not a de Polignac number, because 128642239 - 2⁵ = 128642207 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 128642198 and 128642207.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (128642209) 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 5 ways as a sum of consecutive naturals, for example, 531459 + ... + 531700.

Almost surely, 2^128642239 is an apocalyptic number.

128642239 is a deficient number, since it is larger than the sum of its proper divisors (12758041).

128642239 is a wasteful number, since it uses less digits than its factorization.

128642239 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1063181 (or 1063170 counting only the distinct ones).

The product of its digits is 41472, while the sum is 37.

The square root of 128642239 is about 11342.0562068789. The cubic root of 128642239 is about 504.8099000200.

It can be divided in two parts, 128642 and 239, that added together give a square (128881 = 359²).

The spelling of 128642239 in words is "one hundred twenty-eight million, six hundred forty-two thousand, two hundred thirty-nine".