556663 has 4 divisors (see below), whose sum is σ = 561880. Its totient is φ = 551448.

The previous prime is 556651. The next prime is 556679. The reversal of 556663 is 366655.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 366655 = 5 ⋅73331.

It is a cyclic number.

It is not a de Polignac number, because 556663 - 2¹⁷ = 425591 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (556613) 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 in 3 ways as a sum of consecutive naturals, for example, 2445 + ... + 2662.

It is an arithmetic number, because the mean of its divisors is an integer number (140470).

2⁵⁵⁶⁶⁶³ is an apocalyptic number.

556663 is a deficient number, since it is larger than the sum of its proper divisors (5217).

556663 is a wasteful number, since it uses less digits than its factorization.

556663 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5216.

The product of its digits is 16200, while the sum is 31.

The square root of 556663 is about 746.0985189638. The cubic root of 556663 is about 82.2616567460.

The spelling of 556663 in words is "five hundred fifty-six thousand, six hundred sixty-three".