644225603 has 4 divisors (see below), whose sum is σ = 736257840. Its totient is φ = 552193368.

The previous prime is 644225563. The next prime is 644225629. The reversal of 644225603 is 306522446.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 644225603 - 2¹² = 644221507 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 644225603.

It is not an unprimeable number, because it can be changed into a prime (644225003) by changing a digit.

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 3 ways as a sum of consecutive naturals, for example, 46016108 + ... + 46016121.

It is an arithmetic number, because the mean of its divisors is an integer number (184064460).

Almost surely, 2^644225603 is an apocalyptic number.

644225603 is a deficient number, since it is larger than the sum of its proper divisors (92032237).

644225603 is an equidigital number, since it uses as much as digits as its factorization.

644225603 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 92032236.

The product of its (nonzero) digits is 34560, while the sum is 32.

The square root of 644225603 is about 25381.5996934787. The cubic root of 644225603 is about 863.6663391234. Note that the first 3 decimals are identical.

The spelling of 644225603 in words is "six hundred forty-four million, two hundred twenty-five thousand, six hundred three".