128009638 has 8 divisors (see below), whose sum is σ = 192485160. Its totient is φ = 63847920.

The previous prime is 128009627. The next prime is 128009657. The reversal of 128009638 is 836900821.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a junction number, because it is equal to n+sod(n) for n = 128009597 and 128009606.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 77428 + ... + 79063.

It is an arithmetic number, because the mean of its divisors is an integer number (24060645).

Almost surely, 2^128009638 is an apocalyptic number.

128009638 is a deficient number, since it is larger than the sum of its proper divisors (64475522).

128009638 is a wasteful number, since it uses less digits than its factorization.

128009638 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 156902.

The product of its (nonzero) digits is 20736, while the sum is 37.

The square root of 128009638 is about 11314.1344344143. The cubic root of 128009638 is about 503.9810687229.

The spelling of 128009638 in words is "one hundred twenty-eight million, nine thousand, six hundred thirty-eight".