555581 has 4 divisors (see below), whose sum is σ = 598332. Its totient is φ = 512832.

The previous prime is 555557. The next prime is 555589. The reversal of 555581 is 185555.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 235225 + 320356 = 485^2 + 566^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-555581 is a prime.

It is a super-2 number, since 2×555581² = 617340495122, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (555589) 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, 21356 + ... + 21381.

It is an arithmetic number, because the mean of its divisors is an integer number (149583).

2⁵⁵⁵⁵⁸¹ is an apocalyptic number.

It is an amenable number.

555581 is a deficient number, since it is larger than the sum of its proper divisors (42751).

555581 is a wasteful number, since it uses less digits than its factorization.

555581 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 42750.

The product of its digits is 5000, while the sum is 29.

The square root of 555581 is about 745.3730609567. The cubic root of 555581 is about 82.2083241531.

The spelling of 555581 in words is "five hundred fifty-five thousand, five hundred eighty-one".