217433979709 has 2 divisors, whose sum is σ = 217433979710. Its totient is φ = 217433979708.

The previous prime is 217433979617. The next prime is 217433979811. The reversal of 217433979709 is 907979334712.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 198514802500 + 18919177209 = 445550^2 + 137547^2 .

It is a cyclic number.

It is not a de Polignac number, because 217433979709 - 2³³ = 208844045117 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (217433479709) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 108716989854 + 108716989855.

It is an arithmetic number, because the mean of its divisors is an integer number (108716989855).

Almost surely, 2^217433979709 is an apocalyptic number.

It is an amenable number.

217433979709 is a deficient number, since it is larger than the sum of its proper divisors (1).

217433979709 is an equidigital number, since it uses as much as digits as its factorization.

217433979709 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 18003384, while the sum is 61.

The spelling of 217433979709 in words is "two hundred seventeen billion, four hundred thirty-three million, nine hundred seventy-nine thousand, seven hundred nine".