6443643 has 4 divisors (see below), whose sum is σ = 8591528. Its totient is φ = 4295760.

The previous prime is 6443639. The next prime is 6443677. The reversal of 6443643 is 3463446.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 6443643 - 2² = 6443639 is a prime.

It is a super-2 number, since 2×6443643² = 83041070222898, which contains 22 as substring.

It is a D-number.

It is a Duffinian number.

6443643 is a lucky number.

It is a self number, because there is not a number n which added to its sum of digits gives 6443643.

It is not an unprimeable number, because it can be changed into a prime (6443543) 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, 1073938 + ... + 1073943.

It is an arithmetic number, because the mean of its divisors is an integer number (2147882).

Almost surely, 2^6443643 is an apocalyptic number.

6443643 is a deficient number, since it is larger than the sum of its proper divisors (2147885).

6443643 is a wasteful number, since it uses less digits than its factorization.

6443643 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2147884.

The product of its digits is 20736, while the sum is 30.

The square root of 6443643 is about 2538.4331781633. The cubic root of 6443643 is about 186.0846244594.

The spelling of 6443643 in words is "six million, four hundred forty-three thousand, six hundred forty-three".