12172009 has 4 divisors (see below), whose sum is σ = 12226816. Its totient is φ = 12117204.

The previous prime is 12172003. The next prime is 12172019. The reversal of 12172009 is 90027121.

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: 90027121 = 17 ⋅5295713.

It is a cyclic number.

It is not a de Polignac number, because 12172009 - 2⁵ = 12171977 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (12172003) 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, 27069 + ... + 27514.

It is an arithmetic number, because the mean of its divisors is an integer number (3056704).

Almost surely, 2^12172009 is an apocalyptic number.

It is an amenable number.

12172009 is a deficient number, since it is larger than the sum of its proper divisors (54807).

12172009 is an equidigital number, since it uses as much as digits as its factorization.

12172009 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 54806.

The product of its (nonzero) digits is 252, while the sum is 22.

The square root of 12172009 is about 3488.8406383783. The cubic root of 12172009 is about 230.0315583666.

The spelling of 12172009 in words is "twelve million, one hundred seventy-two thousand, nine".