204863967617 has 8 divisors (see below), whose sum is σ = 209915278440. Its totient is φ = 199815258240.

The previous prime is 204863967601. The next prime is 204863967619. The reversal of 204863967617 is 716769368402.

It can be written as a sum of positive squares in 4 ways, for example, as 50013060496 + 154850907121 = 223636^2 + 393511^2 .

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 204863967617 - 2⁴ = 204863967601 is a prime.

It is not an unprimeable number, because it can be changed into a prime (204863967619) 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 7 ways as a sum of consecutive naturals, for example, 490442 + ... + 806387.

It is an arithmetic number, because the mean of its divisors is an integer number (26239409805).

Almost surely, 2^204863967617 is an apocalyptic number.

It is an amenable number.

204863967617 is a deficient number, since it is larger than the sum of its proper divisors (5051310823).

204863967617 is a wasteful number, since it uses less digits than its factorization.

204863967617 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1300723.

The product of its (nonzero) digits is 18289152, while the sum is 59.

The spelling of 204863967617 in words is "two hundred four billion, eight hundred sixty-three million, nine hundred sixty-seven thousand, six hundred seventeen".