644313120 has 96 divisors (see below), whose sum is σ = 2214112320. Its totient is φ = 156195840.

The previous prime is 644313119. The next prime is 644313127. The reversal of 644313120 is 21313446.

It is a tau number, because it is divible by the number of its divisors (96).

It is a Harshad number since it is a multiple of its sum of digits (24).

It is not an unprimeable number, because it can be changed into a prime (644313127) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 55735 + ... + 66294.

It is an arithmetic number, because the mean of its divisors is an integer number (23063670).

Almost surely, 2^644313120 is an apocalyptic number.

644313120 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

644313120 is an abundant number, since it is smaller than the sum of its proper divisors (1569799200).

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

644313120 is a wasteful number, since it uses less digits than its factorization.

644313120 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 122058 (or 122050 counting only the distinct ones).

The product of its (nonzero) digits is 1728, while the sum is 24.

The square root of 644313120 is about 25383.3236594422. The cubic root of 644313120 is about 863.7054465749.

Adding to 644313120 its reverse (21313446), we get a palindrome (665626566).

The spelling of 644313120 in words is "six hundred forty-four million, three hundred thirteen thousand, one hundred twenty".