12172645 has 4 divisors (see below), whose sum is σ = 14607180. Its totient is φ = 9738112.

The previous prime is 12172609. The next prime is 12172649. The reversal of 12172645 is 54627121.

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

It can be written as a sum of positive squares in 2 ways, for example, as 4866436 + 7306209 = 2206^2 + 2703^2 .

It is a cyclic number.

It is not a de Polignac number, because 12172645 - 2⁹ = 12172133 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12172649) 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, 1217260 + ... + 1217269.

It is an arithmetic number, because the mean of its divisors is an integer number (3651795).

Almost surely, 2^12172645 is an apocalyptic number.

It is an amenable number.

12172645 is a deficient number, since it is larger than the sum of its proper divisors (2434535).

12172645 is an equidigital number, since it uses as much as digits as its factorization.

12172645 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2434534.

The product of its digits is 3360, while the sum is 28.

The square root of 12172645 is about 3488.9317849451. The cubic root of 12172645 is about 230.0355647587.

Adding to 12172645 its reverse (54627121), we get a palindrome (66799766).

It can be divided in two parts, 121726 and 45, that added together give a triangular number (121771 = T₄₉₃).

The spelling of 12172645 in words is "twelve million, one hundred seventy-two thousand, six hundred forty-five".