644341716 has 72 divisors (see below), whose sum is σ = 1693421184. Its totient is φ = 214228800.

The previous prime is 644341703. The next prime is 644341741. The reversal of 644341716 is 617143446.

644341716 is a `hidden beast` number, since 644 + 3 + 4 + 1 + 7 + 1 + 6 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 583621 + ... + 584723.

Almost surely, 2^644341716 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 644341716, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (846710592).

644341716 is an abundant number, since it is smaller than the sum of its proper divisors (1049079468).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

644341716 is a wasteful number, since it uses less digits than its factorization.

644341716 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1723 (or 1709 counting only the distinct ones).

The product of its digits is 48384, while the sum is 36.

The square root of 644341716 is about 25383.8869364012. The cubic root of 644341716 is about 863.7182240868.

The spelling of 644341716 in words is "six hundred forty-four million, three hundred forty-one thousand, seven hundred sixteen".