644304060 has 144 divisors (see below), whose sum is σ = 2146959360. Its totient is φ = 155675520.

The previous prime is 644304047. The next prime is 644304061. The reversal of 644304060 is 60403446.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (644304061) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 74565 + ... + 82755.

It is an arithmetic number, because the mean of its divisors is an integer number (14909440).

Almost surely, 2^644304060 is an apocalyptic number.

644304060 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 644304060, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1073479680).

644304060 is an abundant number, since it is smaller than the sum of its proper divisors (1502655300).

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

644304060 is a wasteful number, since it uses less digits than its factorization.

644304060 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8248 (or 8243 counting only the distinct ones).

The product of its (nonzero) digits is 6912, while the sum is 27.

The square root of 644304060 is about 25383.1451951881. The cubic root of 644304060 is about 863.7013982286.

It can be divided in two parts, 644 and 304060, that added together give a square (304704 = 552²).

The spelling of 644304060 in words is "six hundred forty-four million, three hundred four thousand, sixty".