12391481 has 2 divisors, whose sum is σ = 12391482. Its totient is φ = 12391480.

The previous prime is 12391469. The next prime is 12391493. The reversal of 12391481 is 18419321.

12391481 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a balanced prime because it is at equal distance from previous prime (12391469) and next prime (12391493).

It can be written as a sum of positive squares in only one way, i.e., 12313081 + 78400 = 3509^2 + 280^2 .

It is a cyclic number.

It is not a de Polignac number, because 12391481 - 2¹⁰ = 12390457 is a prime.

It is a super-2 number, since 2×12391481² = 307097602746722, which contains 22 as substring.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (12391451) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6195740 + 6195741.

It is an arithmetic number, because the mean of its divisors is an integer number (6195741).

Almost surely, 2^12391481 is an apocalyptic number.

It is an amenable number.

12391481 is a deficient number, since it is larger than the sum of its proper divisors (1).

12391481 is an equidigital number, since it uses as much as digits as its factorization.

12391481 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1728, while the sum is 29.

The square root of 12391481 is about 3520.1535477874. The cubic root of 12391481 is about 231.4058879757.

The spelling of 12391481 in words is "twelve million, three hundred ninety-one thousand, four hundred eighty-one".