216031217 has 2 divisors, whose sum is σ = 216031218. Its totient is φ = 216031216.

The previous prime is 216031199. The next prime is 216031241. The reversal of 216031217 is 712130612.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 188897536 + 27133681 = 13744^2 + 5209^2 .

It is a cyclic number.

It is not a de Polignac number, because 216031217 - 2¹⁴ = 216014833 is a prime.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 216031192 and 216031201.

It is not a weakly prime, because it can be changed into another prime (216031117) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 108015608 + 108015609.

It is an arithmetic number, because the mean of its divisors is an integer number (108015609).

Almost surely, 2^216031217 is an apocalyptic number.

It is an amenable number.

216031217 is a deficient number, since it is larger than the sum of its proper divisors (1).

216031217 is an equidigital number, since it uses as much as digits as its factorization.

216031217 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 504, while the sum is 23.

The square root of 216031217 is about 14698.0004422370. Note that the first 3 decimals coincide. The cubic root of 216031217 is about 600.0289032373.

Adding to 216031217 its reverse (712130612), we get a palindrome (928161829).

The spelling of 216031217 in words is "two hundred sixteen million, thirty-one thousand, two hundred seventeen".