16561169 has 2 divisors, whose sum is σ = 16561170. Its totient is φ = 16561168.

The previous prime is 16561157. The next prime is 16561187. The reversal of 16561169 is 96116561.

16561169 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 14922769 + 1638400 = 3863^2 + 1280^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-16561169 is a prime.

It is a super-2 number, since 2×16561169² = 548544637293122, which contains 22 as substring.

It is a nialpdrome in base 16.

It is not a weakly prime, because it can be changed into another prime (16561189) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8280584 + 8280585.

It is an arithmetic number, because the mean of its divisors is an integer number (8280585).

Almost surely, 2^16561169 is an apocalyptic number.

It is an amenable number.

16561169 is a deficient number, since it is larger than the sum of its proper divisors (1).

16561169 is an equidigital number, since it uses as much as digits as its factorization.

16561169 is an evil number, because the sum of its binary digits is even.

The product of its digits is 9720, while the sum is 35.

The square root of 16561169 is about 4069.5416203794. The cubic root of 16561169 is about 254.8963772231.

The spelling of 16561169 in words is "sixteen million, five hundred sixty-one thousand, one hundred sixty-nine".