13623209 has 4 divisors (see below), whose sum is σ = 14340240. Its totient is φ = 12906180.

The previous prime is 13623179. The next prime is 13623223. The reversal of 13623209 is 90232631.

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: 90232631 = 2857 ⋅31583.

It is a cyclic number.

It is not a de Polignac number, because 13623209 - 2¹² = 13619113 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (13623299) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 358487 + ... + 358524.

It is an arithmetic number, because the mean of its divisors is an integer number (3585060).

Almost surely, 2^13623209 is an apocalyptic number.

13623209 is a gapful number since it is divisible by the number (19) formed by its first and last digit.

It is an amenable number.

13623209 is a deficient number, since it is larger than the sum of its proper divisors (717031).

13623209 is an equidigital number, since it uses as much as digits as its factorization.

13623209 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 717030.

The product of its (nonzero) digits is 1944, while the sum is 26.

The square root of 13623209 is about 3690.9631534330. The cubic root of 13623209 is about 238.8323433339.

The spelling of 13623209 in words is "thirteen million, six hundred twenty-three thousand, two hundred nine".