644363 has 2 divisors, whose sum is σ = 644364. Its totient is φ = 644362.

The previous prime is 644359. The next prime is 644377. The reversal of 644363 is 363446.

644363 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 not a de Polignac number, because 644363 - 2² = 644359 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (644353) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 322181 + 322182.

It is an arithmetic number, because the mean of its divisors is an integer number (322182).

2⁶⁴⁴³⁶³ is an apocalyptic number.

644363 is a deficient number, since it is larger than the sum of its proper divisors (1).

644363 is an equidigital number, since it uses as much as digits as its factorization.

644363 is an evil number, because the sum of its binary digits is even.

The product of its digits is 5184, while the sum is 26.

The square root of 644363 is about 802.7222433694. The cubic root of 644363 is about 86.3727734142.

The spelling of 644363 in words is "six hundred forty-four thousand, three hundred sixty-three".