6640213 has 2 divisors, whose sum is σ = 6640214. Its totient is φ = 6640212.

The previous prime is 6640181. The next prime is 6640223. The reversal of 6640213 is 3120466.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 5673924 + 966289 = 2382^2 + 983^2 .

It is a cyclic number.

It is not a de Polignac number, because 6640213 - 2⁵ = 6640181 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (6640223) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3320106 + 3320107.

It is an arithmetic number, because the mean of its divisors is an integer number (3320107).

Almost surely, 2^6640213 is an apocalyptic number.

It is an amenable number.

6640213 is a deficient number, since it is larger than the sum of its proper divisors (1).

6640213 is an equidigital number, since it uses as much as digits as its factorization.

6640213 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 864, while the sum is 22.

The square root of 6640213 is about 2576.8610750291. The cubic root of 6640213 is about 187.9579372473.

Adding to 6640213 its reverse (3120466), we get a palindrome (9760679).

The spelling of 6640213 in words is "six million, six hundred forty thousand, two hundred thirteen".