6643387284481 has 6 divisors (see below), whose sum is σ = 6656114307570. Its totient is φ = 6630684550128.

The previous prime is 6643387284449. The next prime is 6643387284533. The reversal of 6643387284481 is 1844827833466.

It can be written as a sum of positive squares in only one way, i.e., 6302108160000 + 341279124481 = 2510400^2 + 584191^2 .

It is not a de Polignac number, because 6643387284481 - 2⁵ = 6643387284449 is a prime.

It is a super-3 number, since 3×6643387284481³ (a number of 39 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (6643387284881) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 11870316 + ... + 12417373.

It is an arithmetic number, because the mean of its divisors is an integer number (1109352384595).

Almost surely, 2^{6643387284481} is an apocalyptic number.

It is an amenable number.

6643387284481 is a deficient number, since it is larger than the sum of its proper divisors (12727023089).

6643387284481 is an frugal number, since it uses more digits than its factorization.

6643387284481 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24288735 (or 24288212 counting only the distinct ones).

The product of its digits is 148635648, while the sum is 64.

The spelling of 6643387284481 in words is "six trillion, six hundred forty-three billion, three hundred eighty-seven million, two hundred eighty-four thousand, four hundred eighty-one".