217993108 has 24 divisors (see below), whose sum is σ = 406003752. Its totient is φ = 102057984.

The previous prime is 217993079. The next prime is 217993117. The reversal of 217993108 is 801399712.

It can be written as a sum of positive squares in 4 ways, for example, as 183277444 + 34715664 = 13538^2 + 5892^2 .

It is a congruent number.

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 7 ways as a sum of consecutive naturals, for example, 5260 + ... + 21532.

It is an arithmetic number, because the mean of its divisors is an integer number (16916823).

Almost surely, 2^217993108 is an apocalyptic number.

It is an amenable number.

217993108 is a deficient number, since it is larger than the sum of its proper divisors (188010644).

217993108 is a wasteful number, since it uses less digits than its factorization.

217993108 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16491 (or 16489 counting only the distinct ones).

The product of its (nonzero) digits is 27216, while the sum is 40.

The square root of 217993108 is about 14764.5896658187. The cubic root of 217993108 is about 601.8398230227.

The spelling of 217993108 in words is "two hundred seventeen million, nine hundred ninety-three thousand, one hundred eight".