12691243 has 2 divisors, whose sum is σ = 12691244. Its totient is φ = 12691242.

The previous prime is 12691223. The next prime is 12691247. The reversal of 12691243 is 34219621.

12691243 is digitally balanced in base 2 and base 3, because in such bases it contains all the possibile digits an equal number of times.

It is a strong prime.

It is an emirp because it is prime and its reverse (34219621) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 12691243 - 2⁹ = 12690731 is a prime.

It is a super-2 number, since 2×12691243² = 322135297770098, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (12691247) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6345621 + 6345622.

It is an arithmetic number, because the mean of its divisors is an integer number (6345622).

Almost surely, 2^12691243 is an apocalyptic number.

12691243 is a deficient number, since it is larger than the sum of its proper divisors (1).

12691243 is an equidigital number, since it uses as much as digits as its factorization.

12691243 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2592, while the sum is 28.

The square root of 12691243 is about 3562.4770876456. The cubic root of 12691243 is about 233.2570183535.

The spelling of 12691243 in words is "twelve million, six hundred ninety-one thousand, two hundred forty-three".