216665353 has 2 divisors, whose sum is σ = 216665354. Its totient is φ = 216665352.

The previous prime is 216665333. The next prime is 216665369. The reversal of 216665353 is 353566612.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 159466384 + 57198969 = 12628^2 + 7563^2 .

It is a cyclic number.

It is not a de Polignac number, because 216665353 - 2⁹ = 216664841 is a prime.

It is a super-3 number, since 3×216665353³ (a number of 26 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is not a weakly prime, because it can be changed into another prime (216665333) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 108332676 + 108332677.

It is an arithmetic number, because the mean of its divisors is an integer number (108332677).

Almost surely, 2^216665353 is an apocalyptic number.

It is an amenable number.

216665353 is a deficient number, since it is larger than the sum of its proper divisors (1).

216665353 is an equidigital number, since it uses as much as digits as its factorization.

216665353 is an evil number, because the sum of its binary digits is even.

The product of its digits is 97200, while the sum is 37.

The square root of 216665353 is about 14719.5568207742. The cubic root of 216665353 is about 600.6154361074.

The spelling of 216665353 in words is "two hundred sixteen million, six hundred sixty-five thousand, three hundred fifty-three".