6444921 has 24 divisors (see below), whose sum is σ = 10588320. Its totient is φ = 3464832.

The previous prime is 6444871. The next prime is 6444937. The reversal of 6444921 is 1294446.

It is not a de Polignac number, because 6444921 - 2¹⁰ = 6443897 is a prime.

It is a Curzon number.

6444921 is a lucky number.

It is not an unprimeable number, because it can be changed into a prime (6444941) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1210 + ... + 3788.

It is an arithmetic number, because the mean of its divisors is an integer number (441180).

Almost surely, 2^6444921 is an apocalyptic number.

It is an amenable number.

6444921 is a deficient number, since it is larger than the sum of its proper divisors (4143399).

6444921 is a wasteful number, since it uses less digits than its factorization.

6444921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2613 (or 2606 counting only the distinct ones).

The product of its digits is 6912, while the sum is 30.

The square root of 6444921 is about 2538.6848957679. The cubic root of 6444921 is about 186.0969260114.

It can be divided in two parts, 644 and 4921, that added together give a triangular number (5565 = T₁₀₅).

The spelling of 6444921 in words is "six million, four hundred forty-four thousand, nine hundred twenty-one".