217104320655 has 40 divisors (see below), whose sum is σ = 397460048832. Its totient is φ = 113325365952.

The previous prime is 217104320599. The next prime is 217104320659. The reversal of 217104320655 is 556023401712.

217104320655 is a `hidden beast` number, since 2 + 171 + 0 + 432 + 0 + 6 + 55 = 666.

It is not a de Polignac number, because 217104320655 - 2¹⁶ = 217104255119 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (217104320659) 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 39 ways as a sum of consecutive naturals, for example, 5683732 + ... + 5721801.

Almost surely, 2^217104320655 is an apocalyptic number.

217104320655 is a deficient number, since it is larger than the sum of its proper divisors (180355728177).

217104320655 is a wasteful number, since it uses less digits than its factorization.

217104320655 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11405597 (or 11405588 counting only the distinct ones).

The product of its (nonzero) digits is 50400, while the sum is 36.

The spelling of 217104320655 in words is "two hundred seventeen billion, one hundred four million, three hundred twenty thousand, six hundred fifty-five".