6444821081 has 4 divisors (see below), whose sum is σ = 6483412992. Its totient is φ = 6406229172.

The previous prime is 6444821069. The next prime is 6444821087. The reversal of 6444821081 is 1801284446.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 6444821081 - 2²⁶ = 6377712217 is a prime.

It is a super-2 number, since 2×6444821081² = 83071437532204017122, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (6444821087) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 19295705 + ... + 19296038.

It is an arithmetic number, because the mean of its divisors is an integer number (1620853248).

Almost surely, 2^6444821081 is an apocalyptic number.

It is an amenable number.

6444821081 is a deficient number, since it is larger than the sum of its proper divisors (38591911).

6444821081 is a wasteful number, since it uses less digits than its factorization.

6444821081 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 38591910.

The product of its (nonzero) digits is 49152, while the sum is 38.

The square root of 6444821081 is about 80279.6430049362. The cubic root of 6444821081 is about 1860.9596428695.

The spelling of 6444821081 in words is "six billion, four hundred forty-four million, eight hundred twenty-one thousand, eighty-one".