217542728818553 has 2 divisors, whose sum is σ = 217542728818554. Its totient is φ = 217542728818552.

The previous prime is 217542728818501. The next prime is 217542728818601. The reversal of 217542728818553 is 355818827245712.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 118964677710649 + 98578051107904 = 10907093^2 + 9928648^2 .

It is a cyclic number.

It is not a de Polignac number, because 217542728818553 - 2¹⁴ = 217542728802169 is a prime.

It is not a weakly prime, because it can be changed into another prime (217542728818153) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 108771364409276 + 108771364409277.

It is an arithmetic number, because the mean of its divisors is an integer number (108771364409277).

Almost surely, 2^{217542728818553} is an apocalyptic number.

It is an amenable number.

217542728818553 is a deficient number, since it is larger than the sum of its proper divisors (1).

217542728818553 is an equidigital number, since it uses as much as digits as its factorization.

217542728818553 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 301056000, while the sum is 68.

The spelling of 217542728818553 in words is "two hundred seventeen trillion, five hundred forty-two billion, seven hundred twenty-eight million, eight hundred eighteen thousand, five hundred fifty-three".