12656121 has 4 divisors (see below), whose sum is σ = 16874832. Its totient is φ = 8437412.

The previous prime is 12656107. The next prime is 12656123. The reversal of 12656121 is 12165621.

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 a de Polignac number, because none of the positive numbers 2^k-12656121 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 12656091 and 12656100.

It is not an unprimeable number, because it can be changed into a prime (12656123) 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, 2109351 + ... + 2109356.

It is an arithmetic number, because the mean of its divisors is an integer number (4218708).

Almost surely, 2^12656121 is an apocalyptic number.

It is an amenable number.

12656121 is a deficient number, since it is larger than the sum of its proper divisors (4218711).

12656121 is an equidigital number, since it uses as much as digits as its factorization.

12656121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4218710.

The product of its digits is 720, while the sum is 24.

The square root of 12656121 is about 3557.5442372513. The cubic root of 12656121 is about 233.0416461750.

The spelling of 12656121 in words is "twelve million, six hundred fifty-six thousand, one hundred twenty-one".