217065949 has 2 divisors, whose sum is σ = 217065950. Its totient is φ = 217065948.

The previous prime is 217065943. The next prime is 217065983. The reversal of 217065949 is 949560712.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 129549924 + 87516025 = 11382^2 + 9355^2 .

It is a cyclic number.

It is not a de Polignac number, because 217065949 - 2³ = 217065941 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (217065941) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 108532974 + 108532975.

It is an arithmetic number, because the mean of its divisors is an integer number (108532975).

Almost surely, 2^217065949 is an apocalyptic number.

It is an amenable number.

217065949 is a deficient number, since it is larger than the sum of its proper divisors (1).

217065949 is an equidigital number, since it uses as much as digits as its factorization.

217065949 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 136080, while the sum is 43.

The square root of 217065949 is about 14733.1581475256. The cubic root of 217065949 is about 600.9853706700.

The spelling of 217065949 in words is "two hundred seventeen million, sixty-five thousand, nine hundred forty-nine".