216577 has 2 divisors, whose sum is σ = 216578. Its totient is φ = 216576.

The previous prime is 216571. The next prime is 216607. The reversal of 216577 is 775612.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 163216 + 53361 = 404^2 + 231^2 .

It is a cyclic number.

It is not a de Polignac number, because 216577 - 2³ = 216569 is a prime.

216577 is a lucky number.

It is not a weakly prime, because it can be changed into another prime (216571) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 108288 + 108289.

It is an arithmetic number, because the mean of its divisors is an integer number (108289).

It is a Proth number, since it is equal to 423 ⋅ 2⁹ + 1 and 423 < 2⁹.

2²¹⁶⁵⁷⁷ is an apocalyptic number.

It is an amenable number.

216577 is a deficient number, since it is larger than the sum of its proper divisors (1).

216577 is an equidigital number, since it uses as much as digits as its factorization.

216577 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2940, while the sum is 28.

The square root of 216577 is about 465.3783407079. The cubic root of 216577 is about 60.0533784242.

The spelling of 216577 in words is "two hundred sixteen thousand, five hundred seventy-seven".