13128217 has 4 divisors (see below), whose sum is σ = 13137460. Its totient is φ = 13118976.

The previous prime is 13128187. The next prime is 13128251. The reversal of 13128217 is 71282131.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 2785561 + 10342656 = 1669^2 + 3216^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-13128217 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 13128191 and 13128200.

It is not an unprimeable number, because it can be changed into a prime (13128257) 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, 1992 + ... + 5497.

It is an arithmetic number, because the mean of its divisors is an integer number (3284365).

Almost surely, 2^13128217 is an apocalyptic number.

It is an amenable number.

13128217 is a deficient number, since it is larger than the sum of its proper divisors (9243).

13128217 is an equidigital number, since it uses as much as digits as its factorization.

13128217 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9242.

The product of its digits is 672, while the sum is 25.

The square root of 13128217 is about 3623.2881475257. The cubic root of 13128217 is about 235.9039695958.

The spelling of 13128217 in words is "thirteen million, one hundred twenty-eight thousand, two hundred seventeen".