216569 has 2 divisors, whose sum is σ = 216570. Its totient is φ = 216568.

The previous prime is 216553. The next prime is 216571. The reversal of 216569 is 965612.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 190969 + 25600 = 437^2 + 160^2 .

It is a cyclic number.

It is not a de Polignac number, because 216569 - 2⁴ = 216553 is a prime.

It is a super-2 number, since 2×216569² = 93804263522, which contains 22 as substring.

Together with 216571, it forms a pair of twin primes.

It is a Chen prime.

It is an alternating number because its digits alternate between even and odd.

It is a nialpdrome in base 13.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 216569.

It is not a weakly prime, because it can be changed into another prime (216509) 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, 108284 + 108285.

It is an arithmetic number, because the mean of its divisors is an integer number (108285).

2²¹⁶⁵⁶⁹ is an apocalyptic number.

It is an amenable number.

216569 is a deficient number, since it is larger than the sum of its proper divisors (1).

216569 is an equidigital number, since it uses as much as digits as its factorization.

216569 is an evil number, because the sum of its binary digits is even.

The product of its digits is 3240, while the sum is 29.

The square root of 216569 is about 465.3697454713. The cubic root of 216569 is about 60.0526389906.

The spelling of 216569 in words is "two hundred sixteen thousand, five hundred sixty-nine".