217820296457 has 2 divisors, whose sum is σ = 217820296458. Its totient is φ = 217820296456.

The previous prime is 217820296423. The next prime is 217820296559. The reversal of 217820296457 is 754692028712.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 182513510656 + 35306785801 = 427216^2 + 187901^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-217820296457 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 217820296399 and 217820296408.

It is not a weakly prime, because it can be changed into another prime (217820296957) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 108910148228 + 108910148229.

It is an arithmetic number, because the mean of its divisors is an integer number (108910148229).

Almost surely, 2^217820296457 is an apocalyptic number.

It is an amenable number.

217820296457 is a deficient number, since it is larger than the sum of its proper divisors (1).

217820296457 is an equidigital number, since it uses as much as digits as its factorization.

217820296457 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3386880, while the sum is 53.

The spelling of 217820296457 in words is "two hundred seventeen billion, eight hundred twenty million, two hundred ninety-six thousand, four hundred fifty-seven".