128779123 has 8 divisors (see below), whose sum is σ = 142868160. Its totient is φ = 115087080.

The previous prime is 128779121. The next prime is 128779127. The reversal of 128779123 is 321977821.

It is a happy number.

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

It is a cyclic number.

It is not a de Polignac number, because 128779123 - 2¹ = 128779121 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (128779121) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 98565 + ... + 99862.

It is an arithmetic number, because the mean of its divisors is an integer number (17858520).

Almost surely, 2^128779123 is an apocalyptic number.

128779123 is a deficient number, since it is larger than the sum of its proper divisors (14089037).

128779123 is a wasteful number, since it uses less digits than its factorization.

128779123 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 198497.

The product of its digits is 42336, while the sum is 40.

The square root of 128779123 is about 11348.0889580581. The cubic root of 128779123 is about 504.9888871194.

The spelling of 128779123 in words is "one hundred twenty-eight million, seven hundred seventy-nine thousand, one hundred twenty-three".