216647 has 2 divisors, whose sum is σ = 216648. Its totient is φ = 216646.

The previous prime is 216641. The next prime is 216649. The reversal of 216647 is 746612.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-216647 is a prime.

Together with 216649, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 216647.

It is not a weakly prime, because it can be changed into another prime (216641) by changing a digit.

It is a good prime.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 108323 + 108324.

It is an arithmetic number, because the mean of its divisors is an integer number (108324).

2²¹⁶⁶⁴⁷ is an apocalyptic number.

216647 is a deficient number, since it is larger than the sum of its proper divisors (1).

216647 is an equidigital number, since it uses as much as digits as its factorization.

216647 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2016, while the sum is 26.

The square root of 216647 is about 465.4535422574. The cubic root of 216647 is about 60.0598476918.

The spelling of 216647 in words is "two hundred sixteen thousand, six hundred forty-seven".