206564641655 has 8 divisors (see below), whose sum is σ = 260923758000. Its totient is φ = 156554254656.

The previous prime is 206564641597. The next prime is 206564641669. The reversal of 206564641655 is 556146465602.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 206564641655 - 2¹⁰ = 206564640631 is a prime.

It is a super-2 number, since 2×206564641655² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1087182230 + ... + 1087182419.

It is an arithmetic number, because the mean of its divisors is an integer number (32615469750).

Almost surely, 2^206564641655 is an apocalyptic number.

206564641655 is a deficient number, since it is larger than the sum of its proper divisors (54359116345).

206564641655 is a wasteful number, since it uses less digits than its factorization.

206564641655 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2174364673.

The product of its (nonzero) digits is 5184000, while the sum is 50.

The spelling of 206564641655 in words is "two hundred six billion, five hundred sixty-four million, six hundred forty-one thousand, six hundred fifty-five".