640572906305 has 4 divisors (see below), whose sum is σ = 768687487572. Its totient is φ = 512458325040.

The previous prime is 640572906283. The next prime is 640572906359. The reversal of 640572906305 is 503609275046.

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

It can be written as a sum of positive squares in 2 ways, for example, as 149328917761 + 491243988544 = 386431^2 + 700888^2 .

It is not a de Polignac number, because 640572906305 - 2¹⁰ = 640572905281 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 640572906305.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 64057290626 + ... + 64057290635.

It is an arithmetic number, because the mean of its divisors is an integer number (192171871893).

Almost surely, 2^640572906305 is an apocalyptic number.

It is an amenable number.

640572906305 is a deficient number, since it is larger than the sum of its proper divisors (128114581267).

640572906305 is a wasteful number, since it uses less digits than its factorization.

640572906305 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 128114581266.

The product of its (nonzero) digits is 1360800, while the sum is 47.

The spelling of 640572906305 in words is "six hundred forty billion, five hundred seventy-two million, nine hundred six thousand, three hundred five".