644425367 has 2 divisors, whose sum is σ = 644425368. Its totient is φ = 644425366.

The previous prime is 644425291. The next prime is 644425373. The reversal of 644425367 is 763524446.

644425367 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 644425367 - 2²² = 640231063 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (644455367) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 322212683 + 322212684.

It is an arithmetic number, because the mean of its divisors is an integer number (322212684).

Almost surely, 2^644425367 is an apocalyptic number.

644425367 is a deficient number, since it is larger than the sum of its proper divisors (1).

644425367 is an equidigital number, since it uses as much as digits as its factorization.

644425367 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 483840, while the sum is 41.

The square root of 644425367 is about 25385.5346014221. The cubic root of 644425367 is about 863.7555995792.

The spelling of 644425367 in words is "six hundred forty-four million, four hundred twenty-five thousand, three hundred sixty-seven".