644355222132 has 24 divisors (see below), whose sum is σ = 1504671078400. Its totient is φ = 214617136896.

The previous prime is 644355222131. The next prime is 644355222151. The reversal of 644355222132 is 231222553446.

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 polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 20976157 + ... + 21006852.

Almost surely, 2^644355222132 is an apocalyptic number.

It is an amenable number.

644355222132 is an abundant number, since it is smaller than the sum of its proper divisors (860315856268).

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

644355222132 is a wasteful number, since it uses less digits than its factorization.

644355222132 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 41984295 (or 41984293 counting only the distinct ones).

The product of its digits is 345600, while the sum is 39.

Adding to 644355222132 its reverse (231222553446), we get a palindrome (875577775578).

The spelling of 644355222132 in words is "six hundred forty-four billion, three hundred fifty-five million, two hundred twenty-two thousand, one hundred thirty-two".