12428021 has 2 divisors, whose sum is σ = 12428022. Its totient is φ = 12428020.

The previous prime is 12428011. The next prime is 12428047. The reversal of 12428021 is 12082421.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 8059921 + 4368100 = 2839^2 + 2090^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-12428021 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 12427984 and 12428002.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (12428011) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6214010 + 6214011.

It is an arithmetic number, because the mean of its divisors is an integer number (6214011).

Almost surely, 2^12428021 is an apocalyptic number.

It is an amenable number.

12428021 is a deficient number, since it is larger than the sum of its proper divisors (1).

12428021 is an equidigital number, since it uses as much as digits as its factorization.

12428021 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 256, while the sum is 20.

The square root of 12428021 is about 3525.3398417741. The cubic root of 12428021 is about 231.6331213326.

The spelling of 12428021 in words is "twelve million, four hundred twenty-eight thousand, twenty-one".