5665661 has 2 divisors, whose sum is σ = 5665662. Its totient is φ = 5665660.

The previous prime is 5665631. The next prime is 5665687. The reversal of 5665661 is 1665665.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 5262436 + 403225 = 2294^2 + 635^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-5665661 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 (5665601) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2832830 + 2832831.

It is an arithmetic number, because the mean of its divisors is an integer number (2832831).

Almost surely, 2^5665661 is an apocalyptic number.

It is an amenable number.

5665661 is a deficient number, since it is larger than the sum of its proper divisors (1).

5665661 is an equidigital number, since it uses as much as digits as its factorization.

5665661 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 5665661 is about 2380.2649012242. The cubic root of 5665661 is about 178.2721607717.

The spelling of 5665661 in words is "five million, six hundred sixty-five thousand, six hundred sixty-one".