13509221 has 8 divisors (see below), whose sum is σ = 14904000. Its totient is φ = 12142240.

The previous prime is 13509217. The next prime is 13509229. The reversal of 13509221 is 12290531.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 13509221 - 2² = 13509217 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (13509229) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5921 + ... + 7878.

It is an arithmetic number, because the mean of its divisors is an integer number (1863000).

Almost surely, 2^13509221 is an apocalyptic number.

13509221 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

13509221 is a deficient number, since it is larger than the sum of its proper divisors (1394779).

13509221 is a wasteful number, since it uses less digits than its factorization.

13509221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13899.

The product of its (nonzero) digits is 540, while the sum is 23.

The square root of 13509221 is about 3675.4892191380. The cubic root of 13509221 is about 238.1643581424.

Adding to 13509221 its reverse (12290531), we get a palindrome (25799752).

The spelling of 13509221 in words is "thirteen million, five hundred nine thousand, two hundred twenty-one".