6400320005 has 8 divisors (see below), whose sum is σ = 7756428024. Its totient is φ = 5069560000.

The previous prime is 6400320001. The next prime is 6400320029. The reversal of 6400320005 is 5000230046.

It is a Cunningham number, because it is equal to 80002²+1.

It can be written as a sum of positive squares in 4 ways, for example, as 1181846884 + 5218473121 = 34378^2 + 72239^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 6400320005 - 2² = 6400320001 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6400320001) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 6336446 + ... + 6337455.

It is an arithmetic number, because the mean of its divisors is an integer number (969553503).

Almost surely, 2^6400320005 is an apocalyptic number.

It is an amenable number.

6400320005 is a deficient number, since it is larger than the sum of its proper divisors (1356108019).

6400320005 is a wasteful number, since it uses less digits than its factorization.

6400320005 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12674007.

The product of its (nonzero) digits is 720, while the sum is 20.

The square root of 6400320005 is about 80002.0000062498. Note that the first 5 decimals coincide. The cubic root of 6400320005 is about 1856.6664773384. Note that the first 3 decimals are identical.

The spelling of 6400320005 in words is "six billion, four hundred million, three hundred twenty thousand, five".