217712421497 has 2 divisors, whose sum is σ = 217712421498. Its totient is φ = 217712421496.

The previous prime is 217712421379. The next prime is 217712421529. The reversal of 217712421497 is 794124217712.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 131689877881 + 86022543616 = 362891^2 + 293296^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-217712421497 is a prime.

It is not a weakly prime, because it can be changed into another prime (217712421197) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 108856210748 + 108856210749.

It is an arithmetic number, because the mean of its divisors is an integer number (108856210749).

Almost surely, 2^217712421497 is an apocalyptic number.

It is an amenable number.

217712421497 is a deficient number, since it is larger than the sum of its proper divisors (1).

217712421497 is an equidigital number, since it uses as much as digits as its factorization.

217712421497 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 395136, while the sum is 47.

The spelling of 217712421497 in words is "two hundred seventeen billion, seven hundred twelve million, four hundred twenty-one thousand, four hundred ninety-seven".