644530037 has 2 divisors, whose sum is σ = 644530038. Its totient is φ = 644530036.

The previous prime is 644530013. The next prime is 644530039. The reversal of 644530037 is 730035446.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 443060401 + 201469636 = 21049^2 + 14194^2 .

It is a cyclic number.

It is not a de Polignac number, because 644530037 - 2¹⁶ = 644464501 is a prime.

Together with 644530039, it forms a pair of twin primes.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 644529985 and 644530012.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (644530039) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 322265018 + 322265019.

It is an arithmetic number, because the mean of its divisors is an integer number (322265019).

Almost surely, 2^644530037 is an apocalyptic number.

It is an amenable number.

644530037 is a deficient number, since it is larger than the sum of its proper divisors (1).

644530037 is an equidigital number, since it uses as much as digits as its factorization.

644530037 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 30240, while the sum is 32.

The square root of 644530037 is about 25387.5961248796. The cubic root of 644530037 is about 863.8023618622.

The spelling of 644530037 in words is "six hundred forty-four million, five hundred thirty thousand, thirty-seven".