644648271 has 8 divisors (see below), whose sum is σ = 869189040. Its totient is φ = 424936512.

The previous prime is 644648269. The next prime is 644648281. The reversal of 644648271 is 172846446.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 644648271 - 2¹ = 644648269 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (644648261) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1206940 + ... + 1207473.

It is an arithmetic number, because the mean of its divisors is an integer number (108648630).

Almost surely, 2^644648271 is an apocalyptic number.

644648271 is a deficient number, since it is larger than the sum of its proper divisors (224540769).

644648271 is a wasteful number, since it uses less digits than its factorization.

644648271 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2414505.

The product of its digits is 258048, while the sum is 42.

The square root of 644648271 is about 25389.9245961858. The cubic root of 644648271 is about 863.8551778978.

The spelling of 644648271 in words is "six hundred forty-four million, six hundred forty-eight thousand, two hundred seventy-one".