5566661 has 2 divisors, whose sum is σ = 5566662. Its totient is φ = 5566660.

The previous prime is 5566657. The next prime is 5566663. The reversal of 5566661 is 1666655.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 5085025 + 481636 = 2255^2 + 694^2 .

It is a cyclic number.

It is not a de Polignac number, because 5566661 - 2² = 5566657 is a prime.

Together with 5566663, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (5566663) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2783330 + 2783331.

It is an arithmetic number, because the mean of its divisors is an integer number (2783331).

Almost surely, 2^5566661 is an apocalyptic number.

It is an amenable number.

5566661 is a deficient number, since it is larger than the sum of its proper divisors (1).

5566661 is an equidigital number, since it uses as much as digits as its factorization.

5566661 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 32400, while the sum is 35.

The square root of 5566661 is about 2359.3772483433. The cubic root of 5566661 is about 177.2276959395.

The spelling of 5566661 in words is "five million, five hundred sixty-six thousand, six hundred sixty-one".