217565157109 has 2 divisors, whose sum is σ = 217565157110. Its totient is φ = 217565157108.

The previous prime is 217565157091. The next prime is 217565157119. The reversal of 217565157109 is 901751565712.

Together with previous prime (217565157091) it forms an Ormiston pair, because they use the same digits, order apart.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 208891960209 + 8673196900 = 457047^2 + 93130^2 .

It is a cyclic number.

It is not a de Polignac number, because 217565157109 - 2¹³ = 217565148917 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (217565157119) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 108782578554 + 108782578555.

It is an arithmetic number, because the mean of its divisors is an integer number (108782578555).

Almost surely, 2^217565157109 is an apocalyptic number.

It is an amenable number.

217565157109 is a deficient number, since it is larger than the sum of its proper divisors (1).

217565157109 is an equidigital number, since it uses as much as digits as its factorization.

217565157109 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 661500, while the sum is 49.

The spelling of 217565157109 in words is "two hundred seventeen billion, five hundred sixty-five million, one hundred fifty-seven thousand, one hundred nine".