216779 has 2 divisors, whose sum is σ = 216780. Its totient is φ = 216778.

The previous prime is 216761. The next prime is 216781. The reversal of 216779 is 977612.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 216779 - 2⁸ = 216523 is a prime.

It is a super-3 number, since 3×216779³ = 30561374333091417, which contains 333 as substring.

Together with 216781, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (216719) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 108389 + 108390.

It is an arithmetic number, because the mean of its divisors is an integer number (108390).

2²¹⁶⁷⁷⁹ is an apocalyptic number.

216779 is a deficient number, since it is larger than the sum of its proper divisors (1).

216779 is an equidigital number, since it uses as much as digits as its factorization.

216779 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 5292, while the sum is 32.

The square root of 216779 is about 465.5953178459. The cubic root of 216779 is about 60.0720430916.

Adding to 216779 its sum of digits (32), we get a triangular number (216811 = T₆₅₈).

The spelling of 216779 in words is "two hundred sixteen thousand, seven hundred seventy-nine".