217906768 has 10 divisors (see below), whose sum is σ = 422194394. Its totient is φ = 108953376.

The previous prime is 217906747. The next prime is 217906771. The reversal of 217906768 is 867609712.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 173923344 + 43983424 = 13188^2 + 6632^2 .

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 as a sum of consecutive naturals, namely, 6809571 + ... + 6809602.

Almost surely, 2^217906768 is an apocalyptic number.

It is an amenable number.

217906768 is a deficient number, since it is larger than the sum of its proper divisors (204287626).

217906768 is a wasteful number, since it uses less digits than its factorization.

217906768 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13619181 (or 13619175 counting only the distinct ones).

The product of its (nonzero) digits is 254016, while the sum is 46.

The square root of 217906768 is about 14761.6654886906. The cubic root of 217906768 is about 601.7603561188.

The spelling of 217906768 in words is "two hundred seventeen million, nine hundred six thousand, seven hundred sixty-eight".