556491 has 16 divisors (see below), whose sum is σ = 842240. Its totient is φ = 324000.

The previous prime is 556487. The next prime is 556513. The reversal of 556491 is 194655.

556491 = T₃₃ + T₃₄ + ... + T₁₄₉.

It is not a de Polignac number, because 556491 - 2² = 556487 is a prime.

It is a Smith number, since the sum of its digits (30) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (556441) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 366 + ... + 1116.

It is an arithmetic number, because the mean of its divisors is an integer number (52640).

2⁵⁵⁶⁴⁹¹ is an apocalyptic number.

556491 is a deficient number, since it is larger than the sum of its proper divisors (285749).

556491 is a wasteful number, since it uses less digits than its factorization.

556491 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 786.

The product of its digits is 5400, while the sum is 30.

The square root of 556491 is about 745.9832437796. The cubic root of 556491 is about 82.2531833593.

The spelling of 556491 in words is "five hundred fifty-six thousand, four hundred ninety-one".