6444689871 has 4 divisors (see below), whose sum is σ = 8592919832. Its totient is φ = 4296459912.

The previous prime is 6444689863. The next prime is 6444689873. The reversal of 6444689871 is 1789864446.

It is a happy number.

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

It is not a de Polignac number, because 6444689871 - 2³ = 6444689863 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 (6444689873) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1074114976 + ... + 1074114981.

It is an arithmetic number, because the mean of its divisors is an integer number (2148229958).

Almost surely, 2^6444689871 is an apocalyptic number.

6444689871 is a deficient number, since it is larger than the sum of its proper divisors (2148229961).

6444689871 is a wasteful number, since it uses less digits than its factorization.

6444689871 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2148229960.

The product of its digits is 9289728, while the sum is 57.

The square root of 6444689871 is about 80278.8257948508. The cubic root of 6444689871 is about 1860.9470137021.

The spelling of 6444689871 in words is "six billion, four hundred forty-four million, six hundred eighty-nine thousand, eight hundred seventy-one".