128857829 has 16 divisors (see below), whose sum is σ = 139968000. Its totient is φ = 118243440.

The previous prime is 128857823. The next prime is 128857831. The reversal of 128857829 is 928758821.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 128857829 - 2²⁴ = 112080613 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (128857823) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 78782 + ... + 80400.

It is an arithmetic number, because the mean of its divisors is an integer number (8748000).

Almost surely, 2^128857829 is an apocalyptic number.

128857829 is a gapful number since it is divisible by the number (19) formed by its first and last digit.

It is an amenable number.

128857829 is a deficient number, since it is larger than the sum of its proper divisors (11110171).

128857829 is a wasteful number, since it uses less digits than its factorization.

128857829 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1768.

The product of its digits is 645120, while the sum is 50.

The square root of 128857829 is about 11351.5562369219. The cubic root of 128857829 is about 505.0917442701.

The spelling of 128857829 in words is "one hundred twenty-eight million, eight hundred fifty-seven thousand, eight hundred twenty-nine".