16517217281 has 2 divisors, whose sum is σ = 16517217282. Its totient is φ = 16517217280.

The previous prime is 16517217257. The next prime is 16517217317. The reversal of 16517217281 is 18271271561.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 11466983056 + 5050234225 = 107084^2 + 71065^2 .

It is an emirp because it is prime and its reverse (18271271561) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-16517217281 is a prime.

It is a super-2 number, since 2×16517217281² (a number of 21 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (16517217251) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8258608640 + 8258608641.

It is an arithmetic number, because the mean of its divisors is an integer number (8258608641).

Almost surely, 2^16517217281 is an apocalyptic number.

It is an amenable number.

16517217281 is a deficient number, since it is larger than the sum of its proper divisors (1).

16517217281 is an equidigital number, since it uses as much as digits as its factorization.

16517217281 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 47040, while the sum is 41.

The spelling of 16517217281 in words is "sixteen billion, five hundred seventeen million, two hundred seventeen thousand, two hundred eighty-one".