12172145 has 4 divisors (see below), whose sum is σ = 14606580. Its totient is φ = 9737712.

The previous prime is 12172133. The next prime is 12172151. The reversal of 12172145 is 54127121.

12172145 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 54127121 = 1597 ⋅33893.

It can be written as a sum of positive squares in 2 ways, for example, as 5841889 + 6330256 = 2417^2 + 2516^2 .

It is a cyclic number.

It is not a de Polignac number, because 12172145 - 2⁶ = 12172081 is a prime.

It is a super-2 number, since 2×12172145² = 296322227802050, which contains 22 as substring.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 12172145.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1217210 + ... + 1217219.

It is an arithmetic number, because the mean of its divisors is an integer number (3651645).

Almost surely, 2^12172145 is an apocalyptic number.

It is an amenable number.

12172145 is a deficient number, since it is larger than the sum of its proper divisors (2434435).

12172145 is an equidigital number, since it uses as much as digits as its factorization.

12172145 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2434434.

The product of its digits is 560, while the sum is 23.

The square root of 12172145 is about 3488.8601290393. The cubic root of 12172145 is about 230.0324150911.

Adding to 12172145 its reverse (54127121), we get a palindrome (66299266).

The spelling of 12172145 in words is "twelve million, one hundred seventy-two thousand, one hundred forty-five".