12861421 has 2 divisors, whose sum is σ = 12861422. Its totient is φ = 12861420.

The previous prime is 12861419. The next prime is 12861427. The reversal of 12861421 is 12416821.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 12859396 + 2025 = 3586^2 + 45^2 .

It is an emirp because it is prime and its reverse (12416821) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 12861421 - 2¹ = 12861419 is a prime.

Together with 12861419, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (12861427) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6430710 + 6430711.

It is an arithmetic number, because the mean of its divisors is an integer number (6430711).

Almost surely, 2^12861421 is an apocalyptic number.

It is an amenable number.

12861421 is a deficient number, since it is larger than the sum of its proper divisors (1).

12861421 is an equidigital number, since it uses as much as digits as its factorization.

12861421 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 768, while the sum is 25.

The square root of 12861421 is about 3586.2823369054. The cubic root of 12861421 is about 234.2949807070.

The spelling of 12861421 in words is "twelve million, eight hundred sixty-one thousand, four hundred twenty-one".