12172543 has 4 divisors (see below), whose sum is σ = 12701808. Its totient is φ = 11643280.

The previous prime is 12172513. The next prime is 12172549. The reversal of 12172543 is 34527121.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 34527121 = 193 ⋅178897.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-12172543 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 (12172549) 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, 264598 + ... + 264643.

It is an arithmetic number, because the mean of its divisors is an integer number (3175452).

Almost surely, 2^12172543 is an apocalyptic number.

12172543 is a deficient number, since it is larger than the sum of its proper divisors (529265).

12172543 is an equidigital number, since it uses as much as digits as its factorization.

12172543 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 529264.

The product of its digits is 1680, while the sum is 25.

The square root of 12172543 is about 3488.9171672598. The cubic root of 12172543 is about 230.0349222335.

Adding to 12172543 its reverse (34527121), we get a palindrome (46699664).

The spelling of 12172543 in words is "twelve million, one hundred seventy-two thousand, five hundred forty-three".