217685660208 has 80 divisors (see below), whose sum is σ = 569573815776. Its totient is φ = 71634124800.

The previous prime is 217685660197. The next prime is 217685660237. The reversal of 217685660208 is 802066586712.

It is a happy number.

It is a hoax number, since the sum of its digits (51) coincides with the sum of the digits of its distinct prime factors.

It is an unprimeable number.

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 15 ways as a sum of consecutive naturals, for example, 1808760 + ... + 1925352.

Almost surely, 2^217685660208 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 217685660208, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (284786907888).

217685660208 is an abundant number, since it is smaller than the sum of its proper divisors (351888155568).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

217685660208 is a wasteful number, since it uses less digits than its factorization.

217685660208 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 117102 (or 117096 counting only the distinct ones).

The product of its (nonzero) digits is 1935360, while the sum is 51.

The spelling of 217685660208 in words is "two hundred seventeen billion, six hundred eighty-five million, six hundred sixty thousand, two hundred eight".