644717483766 has 48 divisors (see below), whose sum is σ = 1443348661248. Its totient is φ = 207771476400.

The previous prime is 644717483747. The next prime is 644717483771. The reversal of 644717483766 is 667384717446.

644717483766 is a `hidden beast` number, since 6 + 4 + 471 + 74 + 8 + 37 + 66 = 666.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 14965 + ... + 1135631.

It is an arithmetic number, because the mean of its divisors is an integer number (30069763776).

Almost surely, 2^644717483766 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 644717483766, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (721674330624).

644717483766 is an abundant number, since it is smaller than the sum of its proper divisors (798631177482).

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

644717483766 is a wasteful number, since it uses less digits than its factorization.

644717483766 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1121737 (or 1121734 counting only the distinct ones).

The product of its digits is 113799168, while the sum is 63.

The spelling of 644717483766 in words is "six hundred forty-four billion, seven hundred seventeen million, four hundred eighty-three thousand, seven hundred sixty-six".