6640640005 has 8 divisors (see below), whose sum is σ = 7985981952. Its totient is φ = 5301036048.

The previous prime is 6640640003. The next prime is 6640640021. The reversal of 6640640005 is 5000460466.

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

It is a cyclic number.

It is not a de Polignac number, because 6640640005 - 2¹ = 6640640003 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 (6640640003) 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 in 7 ways as a sum of consecutive naturals, for example, 1431949 + ... + 1436578.

It is an arithmetic number, because the mean of its divisors is an integer number (998247744).

Almost surely, 2^6640640005 is an apocalyptic number.

It is an amenable number.

6640640005 is a deficient number, since it is larger than the sum of its proper divisors (1345341947).

6640640005 is a wasteful number, since it uses less digits than its factorization.

6640640005 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2868995.

The product of its (nonzero) digits is 17280, while the sum is 31.

The square root of 6640640005 is about 81490.1221314584. The cubic root of 6640640005 is about 1879.6196609689.

The spelling of 6640640005 in words is "six billion, six hundred forty million, six hundred forty thousand, five".