13121209 has 2 divisors, whose sum is σ = 13121210. Its totient is φ = 13121208.

The previous prime is 13121203. The next prime is 13121219. The reversal of 13121209 is 90212131.

13121209 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 8294400 + 4826809 = 2880^2 + 2197^2 .

It is an emirp because it is prime and its reverse (90212131) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 13121209 - 2¹⁷ = 12990137 is a prime.

It is a super-2 number, since 2×13121209² = 344332251243362, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (13121203) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6560604 + 6560605.

It is an arithmetic number, because the mean of its divisors is an integer number (6560605).

Almost surely, 2^13121209 is an apocalyptic number.

It is an amenable number.

13121209 is a deficient number, since it is larger than the sum of its proper divisors (1).

13121209 is an equidigital number, since it uses as much as digits as its factorization.

13121209 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 108, while the sum is 19.

The square root of 13121209 is about 3622.3209410542. The cubic root of 13121209 is about 235.8619859998.

The spelling of 13121209 in words is "thirteen million, one hundred twenty-one thousand, two hundred nine".