644355222133 has 16 divisors (see below), whose sum is σ = 737545052160. Its totient is φ = 551450718000.

The previous prime is 644355222131. The next prime is 644355222151. The reversal of 644355222133 is 331222553446.

It is not a de Polignac number, because 644355222133 - 2¹ = 644355222131 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (644355222131) 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, 14970838 + ... + 15013816.

It is an arithmetic number, because the mean of its divisors is an integer number (46096565760).

Almost surely, 2^644355222133 is an apocalyptic number.

It is an amenable number.

644355222133 is a deficient number, since it is larger than the sum of its proper divisors (93189830027).

644355222133 is a wasteful number, since it uses less digits than its factorization.

644355222133 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 46248.

The product of its digits is 518400, while the sum is 40.

Adding to 644355222133 its reverse (331222553446), we get a palindrome (975577775579).

The spelling of 644355222133 in words is "six hundred forty-four billion, three hundred fifty-five million, two hundred twenty-two thousand, one hundred thirty-three".