13649809 has 4 divisors (see below), whose sum is σ = 14368240. Its totient is φ = 12931380.

The previous prime is 13649803. The next prime is 13649813. The reversal of 13649809 is 90894631.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 90894631 = 17 ⋅5346743.

It is a cyclic number.

It is not a de Polignac number, because 13649809 - 2⁷ = 13649681 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (13649803) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 359187 + ... + 359224.

It is an arithmetic number, because the mean of its divisors is an integer number (3592060).

Almost surely, 2^13649809 is an apocalyptic number.

13649809 is a gapful number since it is divisible by the number (19) formed by its first and last digit.

It is an amenable number.

13649809 is a deficient number, since it is larger than the sum of its proper divisors (718431).

13649809 is an equidigital number, since it uses as much as digits as its factorization.

13649809 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 718430.

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

The square root of 13649809 is about 3694.5647916906. The cubic root of 13649809 is about 238.9876863225.

The spelling of 13649809 in words is "thirteen million, six hundred forty-nine thousand, eight hundred nine".