664431223 has 2 divisors, whose sum is σ = 664431224. Its totient is φ = 664431222.

The previous prime is 664431221. The next prime is 664431289. The reversal of 664431223 is 322134466.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 664431223 - 2¹ = 664431221 is a prime.

Together with 664431221, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (664431221) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 332215611 + 332215612.

It is an arithmetic number, because the mean of its divisors is an integer number (332215612).

Almost surely, 2^664431223 is an apocalyptic number.

664431223 is a deficient number, since it is larger than the sum of its proper divisors (1).

664431223 is an equidigital number, since it uses as much as digits as its factorization.

664431223 is an evil number, because the sum of its binary digits is even.

The product of its digits is 20736, while the sum is 31.

The square root of 664431223 is about 25776.5634443383. The cubic root of 664431223 is about 872.6029513742.

Adding to 664431223 its reverse (322134466), we get a palindrome (986565689).

The spelling of 664431223 in words is "six hundred sixty-four million, four hundred thirty-one thousand, two hundred twenty-three".