644424203 has 2 divisors, whose sum is σ = 644424204. Its totient is φ = 644424202.

The previous prime is 644424163. The next prime is 644424223. The reversal of 644424203 is 302424446.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 644424203 - 2²⁰ = 643375627 is a prime.

It is not a weakly prime, because it can be changed into another prime (644424223) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 322212101 + 322212102.

It is an arithmetic number, because the mean of its divisors is an integer number (322212102).

Almost surely, 2^644424203 is an apocalyptic number.

644424203 is a deficient number, since it is larger than the sum of its proper divisors (1).

644424203 is an equidigital number, since it uses as much as digits as its factorization.

644424203 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 18432, while the sum is 29.

The square root of 644424203 is about 25385.5116749692. The cubic root of 644424203 is about 863.7550795230.

Adding to 644424203 its reverse (302424446), we get a palindrome (946848649).

The spelling of 644424203 in words is "six hundred forty-four million, four hundred twenty-four thousand, two hundred three".