644031171 has 12 divisors (see below), whose sum is σ = 1063162672. Its totient is φ = 368017776.

The previous prime is 644031137. The next prime is 644031173. The reversal of 644031171 is 171130446.

It is a happy number.

644031171 is a `hidden beast` number, since 644 + 0 + 3 + 1 + 17 + 1 = 666.

It is not a de Polignac number, because 644031171 - 2¹⁹ = 643506883 is a prime.

It is a super-2 number, since 2×644031171² = 829552298439262482, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (644031173) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 5111296 + ... + 5111421.

Almost surely, 2^644031171 is an apocalyptic number.

644031171 is a deficient number, since it is larger than the sum of its proper divisors (419131501).

644031171 is a wasteful number, since it uses less digits than its factorization.

644031171 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10222730 (or 10222727 counting only the distinct ones).

The product of its (nonzero) digits is 2016, while the sum is 27.

The square root of 644031171 is about 25377.7692282044. The cubic root of 644031171 is about 863.5794434411.

The spelling of 644031171 in words is "six hundred forty-four million, thirty-one thousand, one hundred seventy-one".