644603478222 has 32 divisors (see below), whose sum is σ = 1406657280384. Its totient is φ = 195299708000.

The previous prime is 644603478191. The next prime is 644603478223. The reversal of 644603478222 is 222874306446.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (644603478223) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 491193 + ... + 1237124.

It is an arithmetic number, because the mean of its divisors is an integer number (43958040012).

Almost surely, 2^644603478222 is an apocalyptic number.

644603478222 is an abundant number, since it is smaller than the sum of its proper divisors (762053802162).

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

644603478222 is a wasteful number, since it uses less digits than its factorization.

644603478222 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1733984.

The product of its (nonzero) digits is 3096576, while the sum is 48.

It can be divided in two parts, 6446034 and 78222, that added together give a palindrome (6524256).

The spelling of 644603478222 in words is "six hundred forty-four billion, six hundred three million, four hundred seventy-eight thousand, two hundred twenty-two".