12347921 has 4 divisors (see below), whose sum is σ = 12364212. Its totient is φ = 12331632.

The previous prime is 12347911. The next prime is 12347953. The reversal of 12347921 is 12974321.

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 2768896 + 9579025 = 1664^2 + 3095^2 .

It is a cyclic number.

It is not a de Polignac number, because 12347921 - 2⁶ = 12347857 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (12347911) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6950 + ... + 8543.

It is an arithmetic number, because the mean of its divisors is an integer number (3091053).

Almost surely, 2^12347921 is an apocalyptic number.

It is an amenable number.

12347921 is a deficient number, since it is larger than the sum of its proper divisors (16291).

12347921 is an equidigital number, since it uses as much as digits as its factorization.

12347921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16290.

The product of its digits is 3024, while the sum is 29.

The square root of 12347921 is about 3513.9608705846. The cubic root of 12347921 is about 231.1344145035.

The spelling of 12347921 in words is "twelve million, three hundred forty-seven thousand, nine hundred twenty-one".