644536363 has 2 divisors, whose sum is σ = 644536364. Its totient is φ = 644536362.

The previous prime is 644536327. The next prime is 644536423. The reversal of 644536363 is 363635446.

It is a happy number.

644536363 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-644536363 is a prime.

It is not a weakly prime, because it can be changed into another prime (644536313) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 322268181 + 322268182.

It is an arithmetic number, because the mean of its divisors is an integer number (322268182).

Almost surely, 2^644536363 is an apocalyptic number.

644536363 is a deficient number, since it is larger than the sum of its proper divisors (1).

644536363 is an equidigital number, since it uses as much as digits as its factorization.

644536363 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 466560, while the sum is 40.

The square root of 644536363 is about 25387.7207129746. The cubic root of 644536363 is about 863.8051878985.

The spelling of 644536363 in words is "six hundred forty-four million, five hundred thirty-six thousand, three hundred sixty-three".