11999209 has 4 divisors (see below), whose sum is σ = 12007504. Its totient is φ = 11990916.

The previous prime is 11999179. The next prime is 11999233. The reversal of 11999209 is 90299911.

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 a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 11999209 - 2⁵ = 11999177 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (11991209) 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, 1347 + ... + 5080.

It is an arithmetic number, because the mean of its divisors is an integer number (3001876).

Almost surely, 2^11999209 is an apocalyptic number.

It is an amenable number.

11999209 is a deficient number, since it is larger than the sum of its proper divisors (8295).

11999209 is an equidigital number, since it uses as much as digits as its factorization.

11999209 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8294.

The product of its (nonzero) digits is 13122, while the sum is 40.

The square root of 11999209 is about 3463.9874422405. The cubic root of 11999209 is about 228.9378180170.

The spelling of 11999209 in words is "eleven million, nine hundred ninety-nine thousand, two hundred nine".