206523311617 has 4 divisors (see below), whose sum is σ = 236026641856. Its totient is φ = 177019981380.

The previous prime is 206523311569. The next prime is 206523311651. The reversal of 206523311617 is 716113325602.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 716113325602 = 2 ⋅358056662801.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-206523311617 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (206523321617) 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, 14751665109 + ... + 14751665122.

It is an arithmetic number, because the mean of its divisors is an integer number (59006660464).

Almost surely, 2^206523311617 is an apocalyptic number.

It is an amenable number.

206523311617 is a deficient number, since it is larger than the sum of its proper divisors (29503330239).

206523311617 is an equidigital number, since it uses as much as digits as its factorization.

206523311617 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 29503330238.

The product of its (nonzero) digits is 45360, while the sum is 37.

The spelling of 206523311617 in words is "two hundred six billion, five hundred twenty-three million, three hundred eleven thousand, six hundred seventeen".