16556585922281 has 2 divisors, whose sum is σ = 16556585922282. Its totient is φ = 16556585922280.

The previous prime is 16556585922277. The next prime is 16556585922293. The reversal of 16556585922281 is 18222958565561.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 8841613045225 + 7714972877056 = 2973485^2 + 2777584^2 .

It is a cyclic number.

It is not a de Polignac number, because 16556585922281 - 2² = 16556585922277 is a prime.

It is a super-2 number, since 2×16556585922281² (a number of 27 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (16556585922781) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8278292961140 + 8278292961141.

It is an arithmetic number, because the mean of its divisors is an integer number (8278292961141).

Almost surely, 2^{16556585922281} is an apocalyptic number.

It is an amenable number.

16556585922281 is a deficient number, since it is larger than the sum of its proper divisors (1).

16556585922281 is an equidigital number, since it uses as much as digits as its factorization.

16556585922281 is an evil number, because the sum of its binary digits is even.

The product of its digits is 103680000, while the sum is 65.

The spelling of 16556585922281 in words is "sixteen trillion, five hundred fifty-six billion, five hundred eighty-five million, nine hundred twenty-two thousand, two hundred eighty-one".