6440443406 has 16 divisors (see below), whose sum is σ = 9924104016. Its totient is φ = 3132449856.

The previous prime is 6440443397. The next prime is 6440443411. The reversal of 6440443406 is 6043440446.

It is a super-2 number, since 2×6440443406² = 82958622531777761672, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 435770 + ... + 450306.

It is an arithmetic number, because the mean of its divisors is an integer number (620256501).

Almost surely, 2^6440443406 is an apocalyptic number.

6440443406 is a deficient number, since it is larger than the sum of its proper divisors (3483660610).

6440443406 is a wasteful number, since it uses less digits than its factorization.

6440443406 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20563.

The product of its (nonzero) digits is 110592, while the sum is 35.

The square root of 6440443406 is about 80252.3732110148. The cubic root of 6440443406 is about 1860.5381922373.

The spelling of 6440443406 in words is "six billion, four hundred forty million, four hundred forty-three thousand, four hundred six".