12172161 has 8 divisors (see below), whose sum is σ = 16254784. Its totient is φ = 8102160.

The previous prime is 12172157. The next prime is 12172163. The reversal of 12172161 is 16127121.

It is a happy number.

12172161 is digitally balanced in base 3, because in such base 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 12172161 - 2² = 12172157 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (12172163) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 610 + ... + 4971.

It is an arithmetic number, because the mean of its divisors is an integer number (2031848).

Almost surely, 2^12172161 is an apocalyptic number.

It is an amenable number.

12172161 is a deficient number, since it is larger than the sum of its proper divisors (4082623).

12172161 is an equidigital number, since it uses as much as digits as its factorization.

12172161 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6311.

The product of its digits is 168, while the sum is 21.

The square root of 12172161 is about 3488.8624220511. The cubic root of 12172161 is about 230.0325158818.

Adding to 12172161 its reverse (16127121), we get a palindrome (28299282).

The spelling of 12172161 in words is "twelve million, one hundred seventy-two thousand, one hundred sixty-one".