644306012 has 48 divisors (see below), whose sum is σ = 1326978240. Its totient is φ = 267950592.

The previous prime is 644305997. The next prime is 644306041. The reversal of 644306012 is 210603446.

644306012 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 588938 + ... + 590030.

It is an arithmetic number, because the mean of its divisors is an integer number (27645380).

Almost surely, 2^644306012 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 644306012, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (663489120).

644306012 is an abundant number, since it is smaller than the sum of its proper divisors (682672228).

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

644306012 is a wasteful number, since it uses less digits than its factorization.

644306012 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1710 (or 1708 counting only the distinct ones).

The product of its (nonzero) digits is 3456, while the sum is 26.

The square root of 644306012 is about 25383.1836458707. The cubic root of 644306012 is about 863.7022704583.

Adding to 644306012 its reverse (210603446), we get a palindrome (854909458).

The spelling of 644306012 in words is "six hundred forty-four million, three hundred six thousand, twelve".