6443987893 has 24 divisors (see below), whose sum is σ = 7613740800. Its totient is φ = 5437137888.

The previous prime is 6443987861. The next prime is 6443987929. The reversal of 6443987893 is 3987893446.

It is not a de Polignac number, because 6443987893 - 2⁵ = 6443987861 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6443987843) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1387371 + ... + 1392007.

It is an arithmetic number, because the mean of its divisors is an integer number (317239200).

Almost surely, 2^6443987893 is an apocalyptic number.

It is an amenable number.

6443987893 is a deficient number, since it is larger than the sum of its proper divisors (1169752907).

6443987893 is a wasteful number, since it uses less digits than its factorization.

6443987893 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5089 (or 5082 counting only the distinct ones).

The product of its digits is 31352832, while the sum is 61.

The square root of 6443987893 is about 80274.4535515503. The cubic root of 6443987893 is about 1860.8794443118.

The spelling of 6443987893 in words is "six billion, four hundred forty-three million, nine hundred eighty-seven thousand, eight hundred ninety-three".