12138261 has 4 divisors (see below), whose sum is σ = 16184352. Its totient is φ = 8092172.

The previous prime is 12138251. The next prime is 12138263. The reversal of 12138261 is 16283121.

12138261 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, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 12138261 - 2⁵ = 12138229 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12138263) 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, 2023041 + ... + 2023046.

It is an arithmetic number, because the mean of its divisors is an integer number (4046088).

Almost surely, 2^12138261 is an apocalyptic number.

It is an amenable number.

12138261 is a deficient number, since it is larger than the sum of its proper divisors (4046091).

12138261 is an equidigital number, since it uses as much as digits as its factorization.

12138261 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4046090.

The product of its digits is 576, while the sum is 24.

The square root of 12138261 is about 3484.0007175659. Note that the first 3 decimals coincide. The cubic root of 12138261 is about 229.8187671245.

The spelling of 12138261 in words is "twelve million, one hundred thirty-eight thousand, two hundred sixty-one".