13181809 has 2 divisors, whose sum is σ = 13181810. Its totient is φ = 13181808.

The previous prime is 13181771. The next prime is 13181827. The reversal of 13181809 is 90818131.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 12496225 + 685584 = 3535^2 + 828^2 .

It is a cyclic number.

It is not a de Polignac number, because 13181809 - 2¹³ = 13173617 is a prime.

It is not a weakly prime, because it can be changed into another prime (13181309) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6590904 + 6590905.

It is an arithmetic number, because the mean of its divisors is an integer number (6590905).

Almost surely, 2^13181809 is an apocalyptic number.

It is an amenable number.

13181809 is a deficient number, since it is larger than the sum of its proper divisors (1).

13181809 is an equidigital number, since it uses as much as digits as its factorization.

13181809 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1728, while the sum is 31.

The square root of 13181809 is about 3630.6761078345. The cubic root of 13181809 is about 236.2245361355.

The spelling of 13181809 in words is "thirteen million, one hundred eighty-one thousand, eight hundred nine".