644050533061 has 8 divisors (see below), whose sum is σ = 693612543960. Its totient is φ = 594491331072.

The previous prime is 644050533053. The next prime is 644050533079. The reversal of 644050533061 is 160335050446.

It can be written as a sum of positive squares in 4 ways, for example, as 43609968900 + 600440564161 = 208830^2 + 774881^2 .

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

It is a cyclic number.

It is not a de Polignac number, because 644050533061 - 2³ = 644050533053 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 644050533061.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (644050533361) 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, 213400 + ... + 1154833.

It is an arithmetic number, because the mean of its divisors is an integer number (86701567995).

Almost surely, 2^644050533061 is an apocalyptic number.

It is an amenable number.

644050533061 is a deficient number, since it is larger than the sum of its proper divisors (49562010899).

644050533061 is a wasteful number, since it uses less digits than its factorization.

644050533061 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1404455.

The product of its (nonzero) digits is 129600, while the sum is 37.

The spelling of 644050533061 in words is "six hundred forty-four billion, fifty million, five hundred thirty-three thousand, sixty-one".