644381353 has 8 divisors (see below), whose sum is σ = 803384640. Its totient is φ = 502115280.

The previous prime is 644381351. The next prime is 644381377. The reversal of 644381353 is 353183446.

644381353 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 644381353 - 2¹ = 644381351 is a prime.

It is a super-2 number, since 2×644381353² = 830454656188221218, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (644381351) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4184218 + ... + 4184371.

It is an arithmetic number, because the mean of its divisors is an integer number (100423080).

Almost surely, 2^644381353 is an apocalyptic number.

It is an amenable number.

644381353 is a deficient number, since it is larger than the sum of its proper divisors (159003287).

644381353 is a wasteful number, since it uses less digits than its factorization.

644381353 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8368607.

The product of its digits is 103680, while the sum is 37.

The square root of 644381353 is about 25384.6676755872. The cubic root of 644381353 is about 863.7359344085.

The spelling of 644381353 in words is "six hundred forty-four million, three hundred eighty-one thousand, three hundred fifty-three".