16566561 has 12 divisors (see below), whose sum is σ = 26105040. Its totient is φ = 10040280.

The previous prime is 16566559. The next prime is 16566587.

16566561 is nontrivially palindromic in base 10.

16566561 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 16566561 - 2¹ = 16566559 is a prime.

It is a nialpdrome in base 16.

It is not an unprimeable number, because it can be changed into a prime (16566761) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 83571 + ... + 83768.

It is an arithmetic number, because the mean of its divisors is an integer number (2175420).

Almost surely, 2^16566561 is an apocalyptic number.

16566561 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

16566561 is a deficient number, since it is larger than the sum of its proper divisors (9538479).

16566561 is a wasteful number, since it uses less digits than its factorization.

16566561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 167356 (or 167353 counting only the distinct ones).

The product of its digits is 32400, while the sum is 36.

The square root of 16566561 is about 4070.2040489391. The cubic root of 16566561 is about 254.9240373505.

The spelling of 16566561 in words is "sixteen million, five hundred sixty-six thousand, five hundred sixty-one".