644424263332 has 6 divisors (see below), whose sum is σ = 1127742460838. Its totient is φ = 322212131664.

The previous prime is 644424263321. The next prime is 644424263339. The reversal of 644424263332 is 233362424446.

It can be written as a sum of positive squares in only one way, i.e., 623761925796 + 20662337536 = 789786^2 + 143744^2 .

It is not an unprimeable number, because it can be changed into a prime (644424263339) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 80553032913 + ... + 80553032920.

Almost surely, 2^644424263332 is an apocalyptic number.

It is an amenable number.

644424263332 is a deficient number, since it is larger than the sum of its proper divisors (483318197506).

644424263332 is a wasteful number, since it uses less digits than its factorization.

644424263332 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 161106065837 (or 161106065835 counting only the distinct ones).

The product of its digits is 1990656, while the sum is 43.

Adding to 644424263332 its reverse (233362424446), we get a palindrome (877786687778).

The spelling of 644424263332 in words is "six hundred forty-four billion, four hundred twenty-four million, two hundred sixty-three thousand, three hundred thirty-two".