556861 has 2 divisors, whose sum is σ = 556862. Its totient is φ = 556860.

The previous prime is 556859. The next prime is 556867. The reversal of 556861 is 168655.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 534361 + 22500 = 731^2 + 150^2 .

It is a cyclic number.

It is not a de Polignac number, because 556861 - 2¹ = 556859 is a prime.

Together with 556859, 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 (556867) 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, 278430 + 278431.

It is an arithmetic number, because the mean of its divisors is an integer number (278431).

2⁵⁵⁶⁸⁶¹ is an apocalyptic number.

It is an amenable number.

556861 is a deficient number, since it is larger than the sum of its proper divisors (1).

556861 is an equidigital number, since it uses as much as digits as its factorization.

556861 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 7200, while the sum is 31.

The square root of 556861 is about 746.2311974181. The cubic root of 556861 is about 82.2714088325.

The spelling of 556861 in words is "five hundred fifty-six thousand, eight hundred sixty-one".