13720909 has 2 divisors, whose sum is σ = 13720910. Its totient is φ = 13720908.

The previous prime is 13720901. The next prime is 13720933. The reversal of 13720909 is 90902731.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 10745284 + 2975625 = 3278^2 + 1725^2 .

It is a cyclic number.

It is not a de Polignac number, because 13720909 - 2³ = 13720901 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (13720901) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6860454 + 6860455.

It is an arithmetic number, because the mean of its divisors is an integer number (6860455).

Almost surely, 2^13720909 is an apocalyptic number.

It is an amenable number.

13720909 is a deficient number, since it is larger than the sum of its proper divisors (1).

13720909 is an equidigital number, since it uses as much as digits as its factorization.

13720909 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 3402, while the sum is 31.

The square root of 13720909 is about 3704.1745369245. The cubic root of 13720909 is about 239.4019193844.

The spelling of 13720909 in words is "thirteen million, seven hundred twenty thousand, nine hundred nine".