16559861 has 2 divisors, whose sum is σ = 16559862. Its totient is φ = 16559860.

The previous prime is 16559821. The next prime is 16559867. The reversal of 16559861 is 16895561.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 11356900 + 5202961 = 3370^2 + 2281^2 .

It is an emirp because it is prime and its reverse (16895561) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 16559861 - 2¹⁰ = 16558837 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (16559867) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a good prime.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8279930 + 8279931.

It is an arithmetic number, because the mean of its divisors is an integer number (8279931).

Almost surely, 2^16559861 is an apocalyptic number.

It is an amenable number.

16559861 is a deficient number, since it is larger than the sum of its proper divisors (1).

16559861 is an equidigital number, since it uses as much as digits as its factorization.

16559861 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 64800, while the sum is 41.

The square root of 16559861 is about 4069.3809111461. The cubic root of 16559861 is about 254.8896664802.

The spelling of 16559861 in words is "sixteen million, five hundred fifty-nine thousand, eight hundred sixty-one".