647640664774511 has 4 divisors (see below), whose sum is σ = 647747836825032. Its totient is φ = 647533492723992.

The previous prime is 647640664774501. The next prime is 647640664774541. The reversal of 647640664774511 is 115477466046746.

647640664774511 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-647640664774511 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 (647640664774501) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 53586016196 + ... + 53586028281.

It is an arithmetic number, because the mean of its divisors is an integer number (161936959206258).

Almost surely, 2^{647640664774511} is an apocalyptic number.

647640664774511 is a deficient number, since it is larger than the sum of its proper divisors (107172050521).

647640664774511 is a wasteful number, since it uses less digits than its factorization.

647640664774511 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 107172050520.

The product of its (nonzero) digits is 568995840, while the sum is 68.

The spelling of 647640664774511 in words is "six hundred forty-seven trillion, six hundred forty billion, six hundred sixty-four million, seven hundred seventy-four thousand, five hundred eleven".