5641661 has 2 divisors, whose sum is σ = 5641662. Its totient is φ = 5641660.

The previous prime is 5641633. The next prime is 5641679. The reversal of 5641661 is 1661465.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 2856100 + 2785561 = 1690^2 + 1669^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-5641661 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 (5641681) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2820830 + 2820831.

It is an arithmetic number, because the mean of its divisors is an integer number (2820831).

Almost surely, 2^5641661 is an apocalyptic number.

It is an amenable number.

5641661 is a deficient number, since it is larger than the sum of its proper divisors (1).

5641661 is an equidigital number, since it uses as much as digits as its factorization.

5641661 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 4320, while the sum is 29.

The square root of 5641661 is about 2375.2180952494. The cubic root of 5641661 is about 178.0200814780.

It can be divided in two parts, 56416 and 61, that multiplied together give a triangular number (3441376 = T₂₆₂₃).

The spelling of 5641661 in words is "five million, six hundred forty-one thousand, six hundred sixty-one".