12171647 has 4 divisors (see below), whose sum is σ = 12812280. Its totient is φ = 11531016.

The previous prime is 12171617. The next prime is 12171659. The reversal of 12171647 is 74617121.

12171647 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.

It is a cyclic number.

It is not a de Polignac number, because 12171647 - 2⁶ = 12171583 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12171617) 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, 320288 + ... + 320325.

It is an arithmetic number, because the mean of its divisors is an integer number (3203070).

Almost surely, 2^12171647 is an apocalyptic number.

12171647 is a deficient number, since it is larger than the sum of its proper divisors (640633).

12171647 is an equidigital number, since it uses as much as digits as its factorization.

12171647 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 640632.

The product of its digits is 2352, while the sum is 29.

The square root of 12171647 is about 3488.7887582942. The cubic root of 12171647 is about 230.0292779364.

Adding to 12171647 its reverse (74617121), we get a palindrome (86788768).

The spelling of 12171647 in words is "twelve million, one hundred seventy-one thousand, six hundred forty-seven".