6443664819 has 32 divisors (see below), whose sum is σ = 9205035840. Its totient is φ = 3995246592.

The previous prime is 6443664817. The next prime is 6443664823. The reversal of 6443664819 is 9184663446.

6443664819 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 6443664819 - 2¹ = 6443664817 is a prime.

It is a super-2 number, since 2×6443664819² = 83041632599236605522, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (51).

It is not an unprimeable number, because it can be changed into a prime (6443664817) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 2405709 + ... + 2408385.

It is an arithmetic number, because the mean of its divisors is an integer number (287657370).

Almost surely, 2^6443664819 is an apocalyptic number.

6443664819 is a deficient number, since it is larger than the sum of its proper divisors (2761371021).

6443664819 is a wasteful number, since it uses less digits than its factorization.

6443664819 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3239.

The product of its digits is 2985984, while the sum is 51.

The square root of 6443664819 is about 80272.4412173942. The cubic root of 6443664819 is about 1860.8483449459.

The spelling of 6443664819 in words is "six billion, four hundred forty-three million, six hundred sixty-four thousand, eight hundred nineteen".