13509391 has 4 divisors (see below), whose sum is σ = 15439312. Its totient is φ = 11579472.

The previous prime is 13509367. The next prime is 13509401. The reversal of 13509391 is 19390531.

13509391 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 13509391 - 2⁵ = 13509359 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (13509341) 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, 964950 + ... + 964963.

It is an arithmetic number, because the mean of its divisors is an integer number (3859828).

Almost surely, 2^13509391 is an apocalyptic number.

13509391 is a deficient number, since it is larger than the sum of its proper divisors (1929921).

13509391 is an equidigital number, since it uses as much as digits as its factorization.

13509391 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1929920.

The product of its (nonzero) digits is 3645, while the sum is 31.

The square root of 13509391 is about 3675.5123452384. The cubic root of 13509391 is about 238.1653571581.

The spelling of 13509391 in words is "thirteen million, five hundred nine thousand, three hundred ninety-one".