128728436 has 12 divisors (see below), whose sum is σ = 225589728. Its totient is φ = 64274232.

The previous prime is 128728433. The next prime is 128728451. The reversal of 128728436 is 634827821.

It is a hoax number, since the sum of its digits (41) coincides with the sum of the digits of its distinct prime factors.

It is a junction number, because it is equal to n+sod(n) for n = 128728393 and 128728402.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (128728433) 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, 19226 + ... + 25041.

It is an arithmetic number, because the mean of its divisors is an integer number (18799144).

Almost surely, 2^128728436 is an apocalyptic number.

It is an amenable number.

128728436 is a deficient number, since it is larger than the sum of its proper divisors (96861292).

128728436 is a wasteful number, since it uses less digits than its factorization.

128728436 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 44998 (or 44996 counting only the distinct ones).

The product of its digits is 129024, while the sum is 41.

The square root of 128728436 is about 11345.8554547465. The cubic root of 128728436 is about 504.9226244881.

The spelling of 128728436 in words is "one hundred twenty-eight million, seven hundred twenty-eight thousand, four hundred thirty-six".