216855329 has 2 divisors, whose sum is σ = 216855330. Its totient is φ = 216855328.

The previous prime is 216855319. The next prime is 216855343. The reversal of 216855329 is 923558612.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 128777104 + 88078225 = 11348^2 + 9385^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-216855329 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (216855319) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 108427664 + 108427665.

It is an arithmetic number, because the mean of its divisors is an integer number (108427665).

Almost surely, 2^216855329 is an apocalyptic number.

It is an amenable number.

216855329 is a deficient number, since it is larger than the sum of its proper divisors (1).

216855329 is an equidigital number, since it uses as much as digits as its factorization.

216855329 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 129600, while the sum is 41.

The square root of 216855329 is about 14726.0085902460. The cubic root of 216855329 is about 600.7909282257.

The spelling of 216855329 in words is "two hundred sixteen million, eight hundred fifty-five thousand, three hundred twenty-nine".