644530049 has 2 divisors, whose sum is σ = 644530050. Its totient is φ = 644530048.

The previous prime is 644530039. The next prime is 644530057. The reversal of 644530049 is 940035446.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 379003024 + 265527025 = 19468^2 + 16295^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-644530049 is a prime.

It is a Chen prime.

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

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 322265024 + 322265025.

It is an arithmetic number, because the mean of its divisors is an integer number (322265025).

Almost surely, 2^644530049 is an apocalyptic number.

It is an amenable number.

644530049 is a deficient number, since it is larger than the sum of its proper divisors (1).

644530049 is an equidigital number, since it uses as much as digits as its factorization.

644530049 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 51840, while the sum is 35.

The square root of 644530049 is about 25387.5963612155. The cubic root of 644530049 is about 863.8023672230.

The spelling of 644530049 in words is "six hundred forty-four million, five hundred thirty thousand, forty-nine".