216766285 has 4 divisors (see below), whose sum is σ = 260119548. Its totient is φ = 173413024.

The previous prime is 216766259. The next prime is 216766321. The reversal of 216766285 is 582667612.

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

It can be written as a sum of positive squares in 2 ways, for example, as 68194564 + 148571721 = 8258^2 + 12189^2 .

It is a cyclic number.

It is not a de Polignac number, because 216766285 - 2¹¹ = 216764237 is a prime.

It is a Duffinian number.

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 3 ways as a sum of consecutive naturals, for example, 21676624 + ... + 21676633.

It is an arithmetic number, because the mean of its divisors is an integer number (65029887).

Almost surely, 2^216766285 is an apocalyptic number.

It is an amenable number.

216766285 is a deficient number, since it is larger than the sum of its proper divisors (43353263).

216766285 is an equidigital number, since it uses as much as digits as its factorization.

216766285 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 43353262.

The product of its digits is 241920, while the sum is 43.

The square root of 216766285 is about 14722.9849215436. The cubic root of 216766285 is about 600.7086857594.

The spelling of 216766285 in words is "two hundred sixteen million, seven hundred sixty-six thousand, two hundred eighty-five".