8398021 has 2 divisors, whose sum is σ = 8398022. Its totient is φ = 8398020.

The previous prime is 8398003. The next prime is 8398067. The reversal of 8398021 is 1208938.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 6477025 + 1920996 = 2545^2 + 1386^2 .

It is a cyclic number.

It is not a de Polignac number, because 8398021 - 2⁹ = 8397509 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (8398321) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4199010 + 4199011.

It is an arithmetic number, because the mean of its divisors is an integer number (4199011).

Almost surely, 2^8398021 is an apocalyptic number.

It is an amenable number.

8398021 is a deficient number, since it is larger than the sum of its proper divisors (1).

8398021 is an equidigital number, since it uses as much as digits as its factorization.

8398021 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 3456, while the sum is 31.

The square root of 8398021 is about 2897.9339191914. The cubic root of 8398021 is about 203.2633062330.

The spelling of 8398021 in words is "eight million, three hundred ninety-eight thousand, twenty-one".