16560406561 has 2 divisors, whose sum is σ = 16560406562. Its totient is φ = 16560406560.

The previous prime is 16560406543. The next prime is 16560406567.

16560406561 is nontrivially palindromic in base 10.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 8455905936 + 8104500625 = 91956^2 + 90025^2 .

It is a palprime.

It is a cyclic number.

It is not a de Polignac number, because 16560406561 - 2³¹ = 14412922913 is a prime.

It is a super-2 number, since 2×16560406561² (a number of 21 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (16560406567) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8280203280 + 8280203281.

It is an arithmetic number, because the mean of its divisors is an integer number (8280203281).

Almost surely, 2^16560406561 is an apocalyptic number.

It is an amenable number.

16560406561 is a deficient number, since it is larger than the sum of its proper divisors (1).

16560406561 is an equidigital number, since it uses as much as digits as its factorization.

16560406561 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 129600, while the sum is 40.

The spelling of 16560406561 in words is "sixteen billion, five hundred sixty million, four hundred six thousand, five hundred sixty-one".