16606561 has 2 divisors, whose sum is σ = 16606562. Its totient is φ = 16606560.

The previous prime is 16606559. The next prime is 16606567. The reversal of 16606561 is 16560661.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 12780625 + 3825936 = 3575^2 + 1956^2 .

It is a cyclic number.

It is not a de Polignac number, because 16606561 - 2¹ = 16606559 is a prime.

Together with 16606559, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (16606567) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8303280 + 8303281.

It is an arithmetic number, because the mean of its divisors is an integer number (8303281).

Almost surely, 2^16606561 is an apocalyptic number.

It is an amenable number.

16606561 is a deficient number, since it is larger than the sum of its proper divisors (1).

16606561 is an equidigital number, since it uses as much as digits as its factorization.

16606561 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 6480, while the sum is 31.

The square root of 16606561 is about 4075.1148450074. The cubic root of 16606561 is about 255.1290440026.

The spelling of 16606561 in words is "sixteen million, six hundred six thousand, five hundred sixty-one".