13509949 has 4 divisors (see below), whose sum is σ = 13519036. Its totient is φ = 13500864.

The previous prime is 13509943. The next prime is 13509967. The reversal of 13509949 is 94990531.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 94990531 = 59 ⋅1610009.

It can be written as a sum of positive squares in 2 ways, for example, as 4995225 + 8514724 = 2235^2 + 2918^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-13509949 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (13509943) 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, 1734 + ... + 5479.

It is an arithmetic number, because the mean of its divisors is an integer number (3379759).

Almost surely, 2^13509949 is an apocalyptic number.

It is an amenable number.

13509949 is a deficient number, since it is larger than the sum of its proper divisors (9087).

13509949 is an equidigital number, since it uses as much as digits as its factorization.

13509949 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9086.

The product of its (nonzero) digits is 43740, while the sum is 40.

The square root of 13509949 is about 3675.5882522394. The cubic root of 13509949 is about 238.1686362212.

The spelling of 13509949 in words is "thirteen million, five hundred nine thousand, nine hundred forty-nine".