6443864738 has 4 divisors (see below), whose sum is σ = 9665797110. Its totient is φ = 3221932368.

The previous prime is 6443864737. The next prime is 6443864767. The reversal of 6443864738 is 8374683446.

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

It can be written as a sum of positive squares in only one way, i.e., 6332498929 + 111365809 = 79577^2 + 10553^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 6443864738.

It is not an unprimeable number, because it can be changed into a prime (6443864731) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1610966183 + ... + 1610966186.

Almost surely, 2^6443864738 is an apocalyptic number.

6443864738 is a deficient number, since it is larger than the sum of its proper divisors (3221932372).

6443864738 is a wasteful number, since it uses less digits than its factorization.

6443864738 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3221932371.

The product of its digits is 9289728, while the sum is 53.

The square root of 6443864738 is about 80273.6864607575. The cubic root of 6443864738 is about 1860.8675894340.

The spelling of 6443864738 in words is "six billion, four hundred forty-three million, eight hundred sixty-four thousand, seven hundred thirty-eight".