216766961 has 6 divisors (see below), whose sum is σ = 221479410. Its totient is φ = 212152736.

The previous prime is 216766951. The next prime is 216766981. The reversal of 216766961 is 169667612.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 109851361 + 106915600 = 10481^2 + 10340^2 .

It is not a de Polignac number, because 216766961 - 2¹⁸ = 216504817 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (216766951) by changing a digit.

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 5 ways as a sum of consecutive naturals, for example, 46856 + ... + 51273.

It is an arithmetic number, because the mean of its divisors is an integer number (36913235).

Almost surely, 2^216766961 is an apocalyptic number.

It is an amenable number.

216766961 is a deficient number, since it is larger than the sum of its proper divisors (4712449).

216766961 is an frugal number, since it uses more digits than its factorization.

216766961 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 98223 (or 98176 counting only the distinct ones).

The product of its digits is 163296, while the sum is 44.

The square root of 216766961 is about 14723.0078788269. The cubic root of 216766961 is about 600.7093102087.

The spelling of 216766961 in words is "two hundred sixteen million, seven hundred sixty-six thousand, nine hundred sixty-one".