12318865921 has 2 divisors, whose sum is σ = 12318865922. Its totient is φ = 12318865920.

The previous prime is 12318865919. The next prime is 12318865931. The reversal of 12318865921 is 12956881321.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 11428679025 + 890186896 = 106905^2 + 29836^2 .

It is a cyclic number.

It is not a de Polignac number, because 12318865921 - 2¹ = 12318865919 is a prime.

Together with 12318865919, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (12318865931) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6159432960 + 6159432961.

It is an arithmetic number, because the mean of its divisors is an integer number (6159432961).

Almost surely, 2^12318865921 is an apocalyptic number.

It is an amenable number.

12318865921 is a deficient number, since it is larger than the sum of its proper divisors (1).

12318865921 is an equidigital number, since it uses as much as digits as its factorization.

12318865921 is an evil number, because the sum of its binary digits is even.

The product of its digits is 207360, while the sum is 46.

The spelling of 12318865921 in words is "twelve billion, three hundred eighteen million, eight hundred sixty-five thousand, nine hundred twenty-one".