217728766456685 has 32 divisors (see below), whose sum is σ = 290547746858880. Its totient is φ = 155283917817600.

The previous prime is 217728766456673. The next prime is 217728766456693. The reversal of 217728766456685 is 586654667827712.

217728766456685 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 217728766456685 - 2¹⁴ = 217728766440301 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 12491711 + ... + 24320780.

It is an arithmetic number, because the mean of its divisors is an integer number (9079617089340).

Almost surely, 2^{217728766456685} is an apocalyptic number.

It is an amenable number.

217728766456685 is a deficient number, since it is larger than the sum of its proper divisors (72818980402195).

217728766456685 is a wasteful number, since it uses less digits than its factorization.

217728766456685 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 36814589.

The product of its digits is 11379916800, while the sum is 80.

The spelling of 217728766456685 in words is "two hundred seventeen trillion, seven hundred twenty-eight billion, seven hundred sixty-six million, four hundred fifty-six thousand, six hundred eighty-five".