644272589 has 2 divisors, whose sum is σ = 644272590. Its totient is φ = 644272588.

The previous prime is 644272561. The next prime is 644272609. The reversal of 644272589 is 985272446.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 363207364 + 281065225 = 19058^2 + 16765^2 .

It is a cyclic number.

It is not a de Polignac number, because 644272589 - 2²⁰ = 643224013 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 (644172589) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 322136294 + 322136295.

It is an arithmetic number, because the mean of its divisors is an integer number (322136295).

Almost surely, 2^644272589 is an apocalyptic number.

It is an amenable number.

644272589 is a deficient number, since it is larger than the sum of its proper divisors (1).

644272589 is an equidigital number, since it uses as much as digits as its factorization.

644272589 is an evil number, because the sum of its binary digits is even.

The product of its digits is 967680, while the sum is 47.

The square root of 644272589 is about 25382.5252683810. The cubic root of 644272589 is about 863.6873355155.

The spelling of 644272589 in words is "six hundred forty-four million, two hundred seventy-two thousand, five hundred eighty-nine".