216505170571 has 2 divisors, whose sum is σ = 216505170572. Its totient is φ = 216505170570.

The previous prime is 216505170491. The next prime is 216505170611. The reversal of 216505170571 is 175071505612.

It is an a-pointer prime, because the next prime (216505170611) can be obtained adding 216505170571 to its sum of digits (40).

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 216505170571 - 2⁷ = 216505170443 is a prime.

It is not a weakly prime, because it can be changed into another prime (216505120571) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 108252585285 + 108252585286.

It is an arithmetic number, because the mean of its divisors is an integer number (108252585286).

Almost surely, 2^216505170571 is an apocalyptic number.

216505170571 is a deficient number, since it is larger than the sum of its proper divisors (1).

216505170571 is an equidigital number, since it uses as much as digits as its factorization.

216505170571 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 73500, while the sum is 40.

The spelling of 216505170571 in words is "two hundred sixteen billion, five hundred five million, one hundred seventy thousand, five hundred seventy-one".