6726221 has 2 divisors, whose sum is σ = 6726222. Its totient is φ = 6726220.

The previous prime is 6726191. The next prime is 6726227. The reversal of 6726221 is 1226276.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 5428900 + 1297321 = 2330^2 + 1139^2 .

It is a cyclic number.

It is not a de Polignac number, because 6726221 - 2⁶ = 6726157 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (6726227) 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, 3363110 + 3363111.

It is an arithmetic number, because the mean of its divisors is an integer number (3363111).

Almost surely, 2^6726221 is an apocalyptic number.

It is an amenable number.

6726221 is a deficient number, since it is larger than the sum of its proper divisors (1).

6726221 is an equidigital number, since it uses as much as digits as its factorization.

6726221 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2016, while the sum is 26.

The square root of 6726221 is about 2593.4959032164. The cubic root of 6726221 is about 188.7659729476.

Subtracting from 6726221 its reverse (1226276), we obtain a palindrome (5499945).

The spelling of 6726221 in words is "six million, seven hundred twenty-six thousand, two hundred twenty-one".