217028471081 has 2 divisors, whose sum is σ = 217028471082. Its totient is φ = 217028471080.

The previous prime is 217028471069. The next prime is 217028471111. The reversal of 217028471081 is 180174820712.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 216443605225 + 584865856 = 465235^2 + 24184^2 .

It is a cyclic number.

It is not a de Polignac number, because 217028471081 - 2¹⁸ = 217028208937 is a prime.

It is a super-2 number, since 2×217028471081² (a number of 23 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (217028471041) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 108514235540 + 108514235541.

It is an arithmetic number, because the mean of its divisors is an integer number (108514235541).

Almost surely, 2^217028471081 is an apocalyptic number.

It is an amenable number.

217028471081 is a deficient number, since it is larger than the sum of its proper divisors (1).

217028471081 is an equidigital number, since it uses as much as digits as its factorization.

217028471081 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 50176, while the sum is 41.

The spelling of 217028471081 in words is "two hundred seventeen billion, twenty-eight million, four hundred seventy-one thousand, eighty-one".