13128209 has 4 divisors (see below), whose sum is σ = 13190640. Its totient is φ = 13065780.

The previous prime is 13128187. The next prime is 13128251. The reversal of 13128209 is 90282131.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 13128209 - 2²⁰ = 12079633 is a prime.

It is a Duffinian number.

It is a nialpdrome in base 16.

It is not an unprimeable number, because it can be changed into a prime (13128289) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 30899 + ... + 31320.

It is an arithmetic number, because the mean of its divisors is an integer number (3297660).

Almost surely, 2^13128209 is an apocalyptic number.

It is an amenable number.

13128209 is a deficient number, since it is larger than the sum of its proper divisors (62431).

13128209 is an equidigital number, since it uses as much as digits as its factorization.

13128209 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 62430.

The product of its (nonzero) digits is 864, while the sum is 26.

The square root of 13128209 is about 3623.2870435559. The cubic root of 13128209 is about 235.9039216778.

The spelling of 13128209 in words is "thirteen million, one hundred twenty-eight thousand, two hundred nine".