12691871 has 2 divisors, whose sum is σ = 12691872. Its totient is φ = 12691870.

The previous prime is 12691849. The next prime is 12691891. The reversal of 12691871 is 17819621.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 12691871 - 2⁶ = 12691807 is a prime.

It is a super-3 number, since 3×12691871³ (a number of 22 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (12691831) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6345935 + 6345936.

It is an arithmetic number, because the mean of its divisors is an integer number (6345936).

Almost surely, 2^12691871 is an apocalyptic number.

12691871 is a deficient number, since it is larger than the sum of its proper divisors (1).

12691871 is an equidigital number, since it uses as much as digits as its factorization.

12691871 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 6048, while the sum is 35.

The square root of 12691871 is about 3562.5652274730. The cubic root of 12691871 is about 233.2608657043.

The spelling of 12691871 in words is "twelve million, six hundred ninety-one thousand, eight hundred seventy-one".