12406421 has 2 divisors, whose sum is σ = 12406422. Its totient is φ = 12406420.

The previous prime is 12406393. The next prime is 12406441. The reversal of 12406421 is 12460421.

It is an a-pointer prime, because the next prime (12406441) can be obtained adding 12406421 to its sum of digits (20).

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 9891025 + 2515396 = 3145^2 + 1586^2 .

It is an emirp because it is prime and its reverse (12460421) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 12406421 - 2⁶ = 12406357 is a prime.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 12406393 and 12406402.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (12406441) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6203210 + 6203211.

It is an arithmetic number, because the mean of its divisors is an integer number (6203211).

Almost surely, 2^12406421 is an apocalyptic number.

It is an amenable number.

12406421 is a deficient number, since it is larger than the sum of its proper divisors (1).

12406421 is an equidigital number, since it uses as much as digits as its factorization.

12406421 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 384, while the sum is 20.

The square root of 12406421 is about 3522.2749750694. The cubic root of 12406421 is about 231.4988501079.

Adding to 12406421 its reverse (12460421), we get a palindrome (24866842).

The spelling of 12406421 in words is "twelve million, four hundred six thousand, four hundred twenty-one".