12388921 has 2 divisors, whose sum is σ = 12388922. Its totient is φ = 12388920.

The previous prime is 12388913. The next prime is 12388949. The reversal of 12388921 is 12988321.

12388921 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 10791225 + 1597696 = 3285^2 + 1264^2 .

It is a cyclic number.

It is not a de Polignac number, because 12388921 - 2³ = 12388913 is a prime.

It is not a weakly prime, because it can be changed into another prime (12388991) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6194460 + 6194461.

It is an arithmetic number, because the mean of its divisors is an integer number (6194461).

Almost surely, 2^12388921 is an apocalyptic number.

It is an amenable number.

12388921 is a deficient number, since it is larger than the sum of its proper divisors (1).

12388921 is an equidigital number, since it uses as much as digits as its factorization.

12388921 is an evil number, because the sum of its binary digits is even.

The product of its digits is 6912, while the sum is 34.

The square root of 12388921 is about 3519.7899085031. The cubic root of 12388921 is about 231.3899512238.

The spelling of 12388921 in words is "twelve million, three hundred eighty-eight thousand, nine hundred twenty-one".