13986409 has 4 divisors (see below), whose sum is σ = 14057604. Its totient is φ = 13915216.

The previous prime is 13986391. The next prime is 13986431. The reversal of 13986409 is 90468931.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 90468931 = 7 ⋅12924133.

It can be written as a sum of positive squares in 2 ways, for example, as 7371225 + 6615184 = 2715^2 + 2572^2 .

It is a cyclic number.

It is not a de Polignac number, because 13986409 - 2⁵ = 13986377 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (13986499) 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 in 3 ways as a sum of consecutive naturals, for example, 35302 + ... + 35695.

It is an arithmetic number, because the mean of its divisors is an integer number (3514401).

Almost surely, 2^13986409 is an apocalyptic number.

It is an amenable number.

13986409 is a deficient number, since it is larger than the sum of its proper divisors (71195).

13986409 is an equidigital number, since it uses as much as digits as its factorization.

13986409 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 71194.

The product of its (nonzero) digits is 46656, while the sum is 40.

The square root of 13986409 is about 3739.8407720116. The cubic root of 13986409 is about 240.9362101104.

The spelling of 13986409 in words is "thirteen million, nine hundred eighty-six thousand, four hundred nine".