640505055005 has 4 divisors (see below), whose sum is σ = 768606066012. Its totient is φ = 512404044000.

The previous prime is 640505054993. The next prime is 640505055017. The reversal of 640505055005 is 500550505046.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 500550505046 = 2 ⋅250275252523.

It is an interprime number because it is at equal distance from previous prime (640505054993) and next prime (640505055017).

It can be written as a sum of positive squares in 2 ways, for example, as 465825360196 + 174679694809 = 682514^2 + 417947^2 .

It is not a de Polignac number, because 640505055005 - 2¹² = 640505050909 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

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 3 ways as a sum of consecutive naturals, for example, 64050505496 + ... + 64050505505.

It is an arithmetic number, because the mean of its divisors is an integer number (192151516503).

Almost surely, 2^640505055005 is an apocalyptic number.

It is an amenable number.

640505055005 is a deficient number, since it is larger than the sum of its proper divisors (128101011007).

640505055005 is a wasteful number, since it uses less digits than its factorization.

640505055005 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 128101011006.

The product of its (nonzero) digits is 75000, while the sum is 35.

The spelling of 640505055005 in words is "six hundred forty billion, five hundred five million, fifty-five thousand, five".