644313271 has 16 divisors (see below), whose sum is σ = 777968640. Its totient is φ = 521871840.

The previous prime is 644313253. The next prime is 644313287. The reversal of 644313271 is 172313446.

It is not a de Polignac number, because 644313271 - 2¹⁷ = 644182199 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (644313871) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 24225 + ... + 43306.

It is an arithmetic number, because the mean of its divisors is an integer number (48623040).

Almost surely, 2^644313271 is an apocalyptic number.

644313271 is a deficient number, since it is larger than the sum of its proper divisors (133655369).

644313271 is a wasteful number, since it uses less digits than its factorization.

644313271 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 67614.

The product of its digits is 12096, while the sum is 31.

The square root of 644313271 is about 25383.3266338358. The cubic root of 644313271 is about 863.7055140470.

The spelling of 644313271 in words is "six hundred forty-four million, three hundred thirteen thousand, two hundred seventy-one".