644430060 has 96 divisors (see below), whose sum is σ = 2012230080. Its totient is φ = 171219456.

The previous prime is 644430041. The next prime is 644430071. The reversal of 644430060 is 60034446.

It is a happy number.

644430060 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 156184 + ... + 160256.

It is an arithmetic number, because the mean of its divisors is an integer number (20960730).

Almost surely, 2^644430060 is an apocalyptic number.

644430060 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 644430060, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1006115040).

644430060 is an abundant number, since it is smaller than the sum of its proper divisors (1367800020).

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

644430060 is a wasteful number, since it uses less digits than its factorization.

644430060 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4384 (or 4376 counting only the distinct ones).

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

The square root of 644430060 is about 25385.6270357854. The cubic root of 644430060 is about 863.7576963284.

The spelling of 644430060 in words is "six hundred forty-four million, four hundred thirty thousand, sixty".