217539396493 has 2 divisors, whose sum is σ = 217539396494. Its totient is φ = 217539396492.

The previous prime is 217539396469. The next prime is 217539396517. The reversal of 217539396493 is 394693935712.

It is a balanced prime because it is at equal distance from previous prime (217539396469) and next prime (217539396517).

It can be written as a sum of positive squares in only one way, i.e., 197439812964 + 20099583529 = 444342^2 + 141773^2 .

It is a cyclic number.

It is not a de Polignac number, because 217539396493 - 2⁹ = 217539395981 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (217539396593) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 108769698246 + 108769698247.

It is an arithmetic number, because the mean of its divisors is an integer number (108769698247).

Almost surely, 2^217539396493 is an apocalyptic number.

It is an amenable number.

217539396493 is a deficient number, since it is larger than the sum of its proper divisors (1).

217539396493 is an equidigital number, since it uses as much as digits as its factorization.

217539396493 is an evil number, because the sum of its binary digits is even.

The product of its digits is 33067440, while the sum is 61.

The spelling of 217539396493 in words is "two hundred seventeen billion, five hundred thirty-nine million, three hundred ninety-six thousand, four hundred ninety-three".