644340112 has 20 divisors (see below), whose sum is σ = 1344440860. Its totient is φ = 297387648.

The previous prime is 644340097. The next prime is 644340119. The reversal of 644340112 is 211043446.

644340112 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 2 ways, for example, as 416813056 + 227527056 = 20416^2 + 15084^2 .

It is not an unprimeable number, because it can be changed into a prime (644340119) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1548687 + ... + 1549102.

It is an arithmetic number, because the mean of its divisors is an integer number (67222043).

Almost surely, 2^644340112 is an apocalyptic number.

It is an amenable number.

644340112 is an abundant number, since it is smaller than the sum of its proper divisors (700100748).

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

644340112 is a wasteful number, since it uses less digits than its factorization.

644340112 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3097810 (or 3097804 counting only the distinct ones).

The product of its (nonzero) digits is 2304, while the sum is 25.

The square root of 644340112 is about 25383.8553415355. The cubic root of 644340112 is about 863.7175073836.

Adding to 644340112 its reverse (211043446), we get a palindrome (855383558).

The spelling of 644340112 in words is "six hundred forty-four million, three hundred forty thousand, one hundred twelve".