206401636564 has 12 divisors (see below), whose sum is σ = 364516652500. Its totient is φ = 102254021568.

The previous prime is 206401636561. The next prime is 206401636591. The reversal of 206401636564 is 465636104602.

It can be written as a sum of positive squares in 2 ways, for example, as 57283635600 + 149118000964 = 239340^2 + 386158^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 206401636564.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (206401636561) by changing a digit.

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, 236698689 + ... + 236699560.

Almost surely, 2^206401636564 is an apocalyptic number.

It is an amenable number.

206401636564 is a deficient number, since it is larger than the sum of its proper divisors (158115015936).

206401636564 is a wasteful number, since it uses less digits than its factorization.

206401636564 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 473398362 (or 473398360 counting only the distinct ones).

The product of its (nonzero) digits is 622080, while the sum is 43.

The spelling of 206401636564 in words is "two hundred six billion, four hundred one million, six hundred thirty-six thousand, five hundred sixty-four".