66631223 has 2 divisors, whose sum is σ = 66631224. Its totient is φ = 66631222.

The previous prime is 66631193. The next prime is 66631277. The reversal of 66631223 is 32213666.

It is a weak prime.

66631223 is a truncatable prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-66631223 is a prime.

It is equal to p_3931319 and since 66631223 and 3931319 have the same sum of digits, it is a Honaker prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (66631283) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33315611 + 33315612.

It is an arithmetic number, because the mean of its divisors is an integer number (33315612).

Almost surely, 2^66631223 is an apocalyptic number.

66631223 is a deficient number, since it is larger than the sum of its proper divisors (1).

66631223 is an equidigital number, since it uses as much as digits as its factorization.

66631223 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 7776, while the sum is 29.

The square root of 66631223 is about 8162.7950482662. The cubic root of 66631223 is about 405.4082617864.

Adding to 66631223 its reverse (32213666), we get a palindrome (98844889).

The spelling of 66631223 in words is "sixty-six million, six hundred thirty-one thousand, two hundred twenty-three".