13531209 has 8 divisors (see below), whose sum is σ = 18228000. Its totient is φ = 8927616.

The previous prime is 13531183. The next prime is 13531229. The reversal of 13531209 is 90213531.

It is a happy number.

13531209 is digitally balanced in base 2 and base 4, because in such bases it contains all the possibile digits an equal number of times.

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

It is not a de Polignac number, because 13531209 - 2¹² = 13527113 is a prime.

It is not an unprimeable number, because it can be changed into a prime (13531229) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 22959 + ... + 23540.

It is an arithmetic number, because the mean of its divisors is an integer number (2278500).

Almost surely, 2^13531209 is an apocalyptic number.

It is an amenable number.

13531209 is a deficient number, since it is larger than the sum of its proper divisors (4696791).

13531209 is an equidigital number, since it uses as much as digits as its factorization.

13531209 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 46599.

The product of its (nonzero) digits is 810, while the sum is 24.

The square root of 13531209 is about 3678.4791694395. The cubic root of 13531209 is about 238.2935025075.

The spelling of 13531209 in words is "thirteen million, five hundred thirty-one thousand, two hundred nine".