556401 has 4 divisors (see below), whose sum is σ = 741872. Its totient is φ = 370932.

The previous prime is 556399. The next prime is 556403. The reversal of 556401 is 104655.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is an interprime number because it is at equal distance from previous prime (556399) and next prime (556403).

It is not a de Polignac number, because 556401 - 2¹ = 556399 is a prime.

It is a D-number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (556403) 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 in 3 ways as a sum of consecutive naturals, for example, 92731 + ... + 92736.

It is an arithmetic number, because the mean of its divisors is an integer number (185468).

2⁵⁵⁶⁴⁰¹ is an apocalyptic number.

It is an amenable number.

556401 is a deficient number, since it is larger than the sum of its proper divisors (185471).

556401 is a wasteful number, since it uses less digits than its factorization.

556401 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 185470.

The product of its (nonzero) digits is 600, while the sum is 21.

The square root of 556401 is about 745.9229182697. The cubic root of 556401 is about 82.2487489147.

The spelling of 556401 in words is "five hundred fifty-six thousand, four hundred one".