13121309 has 2 divisors, whose sum is σ = 13121310. Its totient is φ = 13121308.

The previous prime is 13121291. The next prime is 13121327. The reversal of 13121309 is 90312131.

13121309 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a balanced prime because it is at equal distance from previous prime (13121291) and next prime (13121327).

It can be written as a sum of positive squares in only one way, i.e., 12802084 + 319225 = 3578^2 + 565^2 .

It is a cyclic number.

It is not a de Polignac number, because 13121309 - 2¹⁶ = 13055773 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (13121209) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6560654 + 6560655.

It is an arithmetic number, because the mean of its divisors is an integer number (6560655).

Almost surely, 2^13121309 is an apocalyptic number.

It is an amenable number.

13121309 is a deficient number, since it is larger than the sum of its proper divisors (1).

13121309 is an equidigital number, since it uses as much as digits as its factorization.

13121309 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 162, while the sum is 20.

The square root of 13121309 is about 3622.3347443327. The cubic root of 13121309 is about 235.8625851860.

The spelling of 13121309 in words is "thirteen million, one hundred twenty-one thousand, three hundred nine".