128516779 has 4 divisors (see below), whose sum is σ = 135280840. Its totient is φ = 121752720.

The previous prime is 128516771. The next prime is 128516789. The reversal of 128516779 is 977615821.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 128516779 - 2³ = 128516771 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (128516771) 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, 3382002 + ... + 3382039.

It is an arithmetic number, because the mean of its divisors is an integer number (33820210).

Almost surely, 2^128516779 is an apocalyptic number.

128516779 is a gapful number since it is divisible by the number (19) formed by its first and last digit.

128516779 is a deficient number, since it is larger than the sum of its proper divisors (6764061).

128516779 is an equidigital number, since it uses as much as digits as its factorization.

128516779 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6764060.

The product of its digits is 211680, while the sum is 46.

The square root of 128516779 is about 11336.5241145600. The cubic root of 128516779 is about 504.6457391901.

The spelling of 128516779 in words is "one hundred twenty-eight million, five hundred sixteen thousand, seven hundred seventy-nine".