644144441446 has 8 divisors (see below), whose sum is σ = 1054054540584. Its totient is φ = 292792927920.

The previous prime is 644144441443. The next prime is 644144441491.

644144441446 is nontrivially palindromic in base 10.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a super-2 number, since 2×644144441446² (a number of 24 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 644144441396 and 644144441405.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (644144441443) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 14639646375 + ... + 14639646418.

It is an arithmetic number, because the mean of its divisors is an integer number (131756817573).

Almost surely, 2^644144441446 is an apocalyptic number.

644144441446 is a deficient number, since it is larger than the sum of its proper divisors (409910099138).

644144441446 is a wasteful number, since it uses less digits than its factorization.

644144441446 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 29279292806.

The product of its digits is 2359296, while the sum is 46.

The spelling of 644144441446 in words is "six hundred forty-four billion, one hundred forty-four million, four hundred forty-one thousand, four hundred forty-six".