644050533104 has 80 divisors (see below), whose sum is σ = 1393927211520. Its totient is φ = 285764129280.

The previous prime is 644050533097. The next prime is 644050533107. The reversal of 644050533104 is 401335050446.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (644050533107) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3032372 + ... + 3237804.

It is an arithmetic number, because the mean of its divisors is an integer number (17424090144).

Almost surely, 2^644050533104 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 644050533104, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (696963605760).

644050533104 is an abundant number, since it is smaller than the sum of its proper divisors (749876678416).

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

644050533104 is a wasteful number, since it uses less digits than its factorization.

644050533104 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 205878 (or 205872 counting only the distinct ones).

The product of its (nonzero) digits is 86400, while the sum is 35.

The spelling of 644050533104 in words is "six hundred forty-four billion, fifty million, five hundred thirty-three thousand, one hundred four".