643302555565 has 4 divisors (see below), whose sum is σ = 771963066684. Its totient is φ = 514642044448.

The previous prime is 643302555563. The next prime is 643302555587. The reversal of 643302555565 is 565555203346.

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 68068288201 + 575234267364 = 260899^2 + 758442^2 .

It is a cyclic number.

It is not a de Polignac number, because 643302555565 - 2¹ = 643302555563 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 (643302555563) 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, 64330255552 + ... + 64330255561.

It is an arithmetic number, because the mean of its divisors is an integer number (192990766671).

Almost surely, 2^643302555565 is an apocalyptic number.

It is an amenable number.

643302555565 is a deficient number, since it is larger than the sum of its proper divisors (128660511119).

643302555565 is a wasteful number, since it uses less digits than its factorization.

643302555565 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 128660511118.

The product of its (nonzero) digits is 8100000, while the sum is 49.

The spelling of 643302555565 in words is "six hundred forty-three billion, three hundred two million, five hundred fifty-five thousand, five hundred sixty-five".