216565289 has 2 divisors, whose sum is σ = 216565290. Its totient is φ = 216565288.

The previous prime is 216565277. The next prime is 216565333. The reversal of 216565289 is 982565612.

It is an a-pointer prime, because the next prime (216565333) can be obtained adding 216565289 to its sum of digits (44).

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 172475689 + 44089600 = 13133^2 + 6640^2 .

It is a cyclic number.

It is not a de Polignac number, because 216565289 - 2⁴ = 216565273 is a prime.

It is not a weakly prime, because it can be changed into another prime (216565229) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 108282644 + 108282645.

It is an arithmetic number, because the mean of its divisors is an integer number (108282645).

Almost surely, 2^216565289 is an apocalyptic number.

It is an amenable number.

216565289 is a deficient number, since it is larger than the sum of its proper divisors (1).

216565289 is an equidigital number, since it uses as much as digits as its factorization.

216565289 is an evil number, because the sum of its binary digits is even.

The product of its digits is 259200, while the sum is 44.

The square root of 216565289 is about 14716.1574128575. The cubic root of 216565289 is about 600.5229597967.

The spelling of 216565289 in words is "two hundred sixteen million, five hundred sixty-five thousand, two hundred eighty-nine".