201218931217 has 2 divisors, whose sum is σ = 201218931218. Its totient is φ = 201218931216.

The previous prime is 201218931131. The next prime is 201218931239. The reversal of 201218931217 is 712139812102.

It is a happy number.

201218931217 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 191317885201 + 9901046016 = 437399^2 + 99504^2 .

It is a cyclic number.

It is not a de Polignac number, because 201218931217 - 2¹⁵ = 201218898449 is a prime.

It is a super-2 number, since 2×201218931217² (a number of 23 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (201218931317) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 100609465608 + 100609465609.

It is an arithmetic number, because the mean of its divisors is an integer number (100609465609).

Almost surely, 2^201218931217 is an apocalyptic number.

It is an amenable number.

201218931217 is a deficient number, since it is larger than the sum of its proper divisors (1).

201218931217 is an equidigital number, since it uses as much as digits as its factorization.

201218931217 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 12096, while the sum is 37.

The spelling of 201218931217 in words is "two hundred one billion, two hundred eighteen million, nine hundred thirty-one thousand, two hundred seventeen".