644552352 has 144 divisors (see below), whose sum is σ = 1962061920. Its totient is φ = 200102400.

The previous prime is 644552317. The next prime is 644552369. The reversal of 644552352 is 253255446.

644552352 is a `hidden beast` number, since 644 + 5 + 5 + 2 + 3 + 5 + 2 = 666.

It is a tau number, because it is divible by the number of its divisors (144).

It is a super-3 number, since 3×644552352³ (a number of 27 digits) contains 333 as substring.

It is a hoax number, since the sum of its digits (36) coincides with the sum of the digits of its distinct prime factors.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 332827 + ... + 334757.

It is an arithmetic number, because the mean of its divisors is an integer number (13625430).

Almost surely, 2^644552352 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 644552352, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (981030960).

644552352 is an abundant number, since it is smaller than the sum of its proper divisors (1317509568).

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

644552352 is a wasteful number, since it uses less digits than its factorization.

644552352 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2027 (or 2016 counting only the distinct ones).

The product of its digits is 144000, while the sum is 36.

The square root of 644552352 is about 25388.0356073486. The cubic root of 644552352 is about 863.8123306385.

The spelling of 644552352 in words is "six hundred forty-four million, five hundred fifty-two thousand, three hundred fifty-two".