6640223 has 2 divisors, whose sum is σ = 6640224. Its totient is φ = 6640222.

The previous prime is 6640213. The next prime is 6640241. The reversal of 6640223 is 3220466.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 6640223 - 2¹² = 6636127 is a prime.

It is a super-2 number, since 2×6640223² = 88185122979458, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (6640213) 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, 3320111 + 3320112.

It is an arithmetic number, because the mean of its divisors is an integer number (3320112).

Almost surely, 2^6640223 is an apocalyptic number.

6640223 is a deficient number, since it is larger than the sum of its proper divisors (1).

6640223 is an equidigital number, since it uses as much as digits as its factorization.

6640223 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1728, while the sum is 23.

The square root of 6640223 is about 2576.8630153735. The cubic root of 6640223 is about 187.9580316006.

Adding to 6640223 its reverse (3220466), we get a palindrome (9860689).

The spelling of 6640223 in words is "six million, six hundred forty thousand, two hundred twenty-three".