217238129 has 2 divisors, whose sum is σ = 217238130. Its totient is φ = 217238128.

The previous prime is 217238083. The next prime is 217238143. The reversal of 217238129 is 921832712.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 203347600 + 13890529 = 14260^2 + 3727^2 .

It is a cyclic number.

It is not a de Polignac number, because 217238129 - 2²⁰ = 216189553 is a prime.

It is not a weakly prime, because it can be changed into another prime (217238179) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 108619064 + 108619065.

It is an arithmetic number, because the mean of its divisors is an integer number (108619065).

Almost surely, 2^217238129 is an apocalyptic number.

It is an amenable number.

217238129 is a deficient number, since it is larger than the sum of its proper divisors (1).

217238129 is an equidigital number, since it uses as much as digits as its factorization.

217238129 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 12096, while the sum is 35.

The square root of 217238129 is about 14739.0002713888. Note that the first 3 decimals coincide. The cubic root of 217238129 is about 601.1442322412.

The spelling of 217238129 in words is "two hundred seventeen million, two hundred thirty-eight thousand, one hundred twenty-nine".