13128979 has 4 divisors (see below), whose sum is σ = 13449240. Its totient is φ = 12808720.

The previous prime is 13128971. The next prime is 13128991. The reversal of 13128979 is 97982131.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 97982131 = 13 ⋅7537087.

It is a cyclic number.

It is not a de Polignac number, because 13128979 - 2³ = 13128971 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (13128971) by changing a digit.

It is an upside-down number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 160069 + ... + 160150.

It is an arithmetic number, because the mean of its divisors is an integer number (3362310).

Almost surely, 2^13128979 is an apocalyptic number.

13128979 is a deficient number, since it is larger than the sum of its proper divisors (320261).

13128979 is an equidigital number, since it uses as much as digits as its factorization.

13128979 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 320260.

The product of its digits is 27216, while the sum is 40.

The square root of 13128979 is about 3623.3932991051. The cubic root of 13128979 is about 235.9085336923.

The spelling of 13128979 in words is "thirteen million, one hundred twenty-eight thousand, nine hundred seventy-nine".