9821213 has 2 divisors, whose sum is σ = 9821214. Its totient is φ = 9821212.

The previous prime is 9821173. The next prime is 9821219. The reversal of 9821213 is 3121289.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 9078169 + 743044 = 3013^2 + 862^2 .

It is a cyclic number.

It is not a de Polignac number, because 9821213 - 2⁸ = 9820957 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (9821219) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4910606 + 4910607.

It is an arithmetic number, because the mean of its divisors is an integer number (4910607).

Almost surely, 2^9821213 is an apocalyptic number.

It is an amenable number.

9821213 is a deficient number, since it is larger than the sum of its proper divisors (1).

9821213 is an equidigital number, since it uses as much as digits as its factorization.

9821213 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 864, while the sum is 26.

The square root of 9821213 is about 3133.8814591493. The cubic root of 9821213 is about 214.1517905827.

The spelling of 9821213 in words is "nine million, eight hundred twenty-one thousand, two hundred thirteen".