6443921 has 8 divisors (see below), whose sum is σ = 7149600. Its totient is φ = 5758240.

The previous prime is 6443917. The next prime is 6443947. The reversal of 6443921 is 1293446.

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

It is a cyclic number.

It is not a de Polignac number, because 6443921 - 2² = 6443917 is a prime.

It is a d-powerful number, because it can be written as 6² + 4⁵ + 4⁸ + 3¹³ + 9⁷ + 2⁵ + 1 .

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (6443911) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4316 + ... + 5613.

It is an arithmetic number, because the mean of its divisors is an integer number (893700).

Almost surely, 2^6443921 is an apocalyptic number.

It is an amenable number.

6443921 is a deficient number, since it is larger than the sum of its proper divisors (705679).

6443921 is a wasteful number, since it uses less digits than its factorization.

6443921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9999.

The product of its digits is 5184, while the sum is 29.

The square root of 6443921 is about 2538.4879357602. The cubic root of 6443921 is about 186.0873005223.

The spelling of 6443921 in words is "six million, four hundred forty-three thousand, nine hundred twenty-one".