12421181 has 4 divisors (see below), whose sum is σ = 12428892. Its totient is φ = 12413472.

The previous prime is 12421177. The next prime is 12421183. The reversal of 12421181 is 18112421.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 18112421 = 109 ⋅166169.

It can be written as a sum of positive squares in 2 ways, for example, as 2149156 + 10272025 = 1466^2 + 3205^2 .

It is a cyclic number.

It is not a de Polignac number, because 12421181 - 2² = 12421177 is a prime.

It is a super-2 number, since 2×12421181² = 308571474869522, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12421183) 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 3 ways as a sum of consecutive naturals, for example, 416 + ... + 5001.

It is an arithmetic number, because the mean of its divisors is an integer number (3107223).

Almost surely, 2^12421181 is an apocalyptic number.

It is an amenable number.

12421181 is a deficient number, since it is larger than the sum of its proper divisors (7711).

12421181 is an equidigital number, since it uses as much as digits as its factorization.

12421181 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7710.

The product of its digits is 128, while the sum is 20.

The square root of 12421181 is about 3524.3695890187. The cubic root of 12421181 is about 231.5906189556.

The spelling of 12421181 in words is "twelve million, four hundred twenty-one thousand, one hundred eighty-one".