217152345209 has 2 divisors, whose sum is σ = 217152345210. Its totient is φ = 217152345208.

The previous prime is 217152345173. The next prime is 217152345217. The reversal of 217152345209 is 902543251712.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 156774026809 + 60378318400 = 395947^2 + 245720^2 .

It is a cyclic number.

It is not a de Polignac number, because 217152345209 - 2³² = 212857377913 is a prime.

It is not a weakly prime, because it can be changed into another prime (217152345229) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 108576172604 + 108576172605.

It is an arithmetic number, because the mean of its divisors is an integer number (108576172605).

Almost surely, 2^217152345209 is an apocalyptic number.

It is an amenable number.

217152345209 is a deficient number, since it is larger than the sum of its proper divisors (1).

217152345209 is an equidigital number, since it uses as much as digits as its factorization.

217152345209 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 151200, while the sum is 41.

The spelling of 217152345209 in words is "two hundred seventeen billion, one hundred fifty-two million, three hundred forty-five thousand, two hundred nine".