12431821 has 2 divisors, whose sum is σ = 12431822. Its totient is φ = 12431820.

The previous prime is 12431813. The next prime is 12431843. The reversal of 12431821 is 12813421.

It is a happy number.

It is an a-pointer prime, because the next prime (12431843) can be obtained adding 12431821 to its sum of digits (22).

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 8916196 + 3515625 = 2986^2 + 1875^2 .

It is a cyclic number.

It is not a de Polignac number, because 12431821 - 2³ = 12431813 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 12431792 and 12431801.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (12431801) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6215910 + 6215911.

It is an arithmetic number, because the mean of its divisors is an integer number (6215911).

Almost surely, 2^12431821 is an apocalyptic number.

It is an amenable number.

12431821 is a deficient number, since it is larger than the sum of its proper divisors (1).

12431821 is an equidigital number, since it uses as much as digits as its factorization.

12431821 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 384, while the sum is 22.

The square root of 12431821 is about 3525.8787557147. The cubic root of 12431821 is about 231.6567270261.

The spelling of 12431821 in words is "twelve million, four hundred thirty-one thousand, eight hundred twenty-one".