128689172 has 12 divisors (see below), whose sum is σ = 225528660. Its totient is φ = 64252416.

The previous prime is 128689139. The next prime is 128689177. The reversal of 128689172 is 271986821.

It can be written as a sum of positive squares in 2 ways, for example, as 41938576 + 86750596 = 6476^2 + 9314^2 .

It is a hoax number, since the sum of its digits (44) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (128689177) by changing a digit.

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, 19853 + ... + 25524.

It is an arithmetic number, because the mean of its divisors is an integer number (18794055).

Almost surely, 2^128689172 is an apocalyptic number.

It is an amenable number.

128689172 is a deficient number, since it is larger than the sum of its proper divisors (96839488).

128689172 is a wasteful number, since it uses less digits than its factorization.

128689172 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 46090 (or 46088 counting only the distinct ones).

The product of its digits is 96768, while the sum is 44.

The square root of 128689172 is about 11344.1249993113. The cubic root of 128689172 is about 504.8712830788.

The spelling of 128689172 in words is "one hundred twenty-eight million, six hundred eighty-nine thousand, one hundred seventy-two".