128311979 has 8 divisors (see below), whose sum is σ = 132888000. Its totient is φ = 123746112.

The previous prime is 128311969. The next prime is 128311987. The reversal of 128311979 is 979113821.

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 128311979 - 2⁸ = 128311723 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (128311969) 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, 30782 + ... + 34700.

It is an arithmetic number, because the mean of its divisors is an integer number (16611000).

Almost surely, 2^128311979 is an apocalyptic number.

128311979 is a deficient number, since it is larger than the sum of its proper divisors (4576021).

128311979 is a wasteful number, since it uses less digits than its factorization.

128311979 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5077.

The product of its digits is 27216, while the sum is 41.

The square root of 128311979 is about 11327.4877620768. The cubic root of 128311979 is about 504.3775345350.

The spelling of 128311979 in words is "one hundred twenty-eight million, three hundred eleven thousand, nine hundred seventy-nine".