217668078854 has 4 divisors (see below), whose sum is σ = 326502118284. Its totient is φ = 108834039426.

The previous prime is 217668078791. The next prime is 217668078889. The reversal of 217668078854 is 458870866712.

It is a semiprime because it is the product of two primes.

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, 54417019712 + ... + 54417019715.

It is an arithmetic number, because the mean of its divisors is an integer number (81625529571).

Almost surely, 2^217668078854 is an apocalyptic number.

217668078854 is a deficient number, since it is larger than the sum of its proper divisors (108834039430).

217668078854 is a wasteful number, since it uses less digits than its factorization.

217668078854 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 108834039429.

The product of its (nonzero) digits is 36126720, while the sum is 62.

The spelling of 217668078854 in words is "two hundred seventeen billion, six hundred sixty-eight million, seventy-eight thousand, eight hundred fifty-four".