217785587713 has 2 divisors, whose sum is σ = 217785587714. Its totient is φ = 217785587712.

The previous prime is 217785587693. The next prime is 217785587717. The reversal of 217785587713 is 317785587712.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 208673548864 + 9112038849 = 456808^2 + 95457^2 .

It is a cyclic number.

It is not a de Polignac number, because 217785587713 - 2¹³ = 217785579521 is a prime.

It is not a weakly prime, because it can be changed into another prime (217785587717) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 108892793856 + 108892793857.

It is an arithmetic number, because the mean of its divisors is an integer number (108892793857).

Almost surely, 2^217785587713 is an apocalyptic number.

It is an amenable number.

217785587713 is a deficient number, since it is larger than the sum of its proper divisors (1).

217785587713 is an equidigital number, since it uses as much as digits as its factorization.

217785587713 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 23049600, while the sum is 61.

Subtracting 217785587713 from its reverse (317785587712), we obtain a palindrome (99999999999).

The spelling of 217785587713 in words is "two hundred seventeen billion, seven hundred eighty-five million, five hundred eighty-seven thousand, seven hundred thirteen".