12172191 has 4 divisors (see below), whose sum is σ = 16229592. Its totient is φ = 8114792.

The previous prime is 12172189. The next prime is 12172219. The reversal of 12172191 is 19127121.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 12172191 - 2¹ = 12172189 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12172151) 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, 2028696 + ... + 2028701.

It is an arithmetic number, because the mean of its divisors is an integer number (4057398).

Almost surely, 2^12172191 is an apocalyptic number.

12172191 is a deficient number, since it is larger than the sum of its proper divisors (4057401).

12172191 is an equidigital number, since it uses as much as digits as its factorization.

12172191 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4057400.

The product of its digits is 252, while the sum is 24.

The square root of 12172191 is about 3488.8667214441. The cubic root of 12172191 is about 230.0327048641.

The spelling of 12172191 in words is "twelve million, one hundred seventy-two thousand, one hundred ninety-one".