8555581 has 4 divisors (see below), whose sum is σ = 8754592. Its totient is φ = 8356572.

The previous prime is 8555579. The next prime is 8555587. The reversal of 8555581 is 1855558.

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, and also an emirpimes, since its reverse is a distinct semiprime: 1855558 = 2 ⋅927779.

It is a cyclic number.

It is not a de Polignac number, because 8555581 - 2¹ = 8555579 is a prime.

It is a super-2 number, since 2×8555581² = 146395932495122, which contains 22 as substring.

It is a Duffinian number.

8555581 is a lucky number.

It is a self number, because there is not a number n which added to its sum of digits gives 8555581.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (8555587) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 99441 + ... + 99526.

It is an arithmetic number, because the mean of its divisors is an integer number (2188648).

Almost surely, 2^8555581 is an apocalyptic number.

It is an amenable number.

8555581 is a deficient number, since it is larger than the sum of its proper divisors (199011).

8555581 is a wasteful number, since it uses less digits than its factorization.

8555581 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 199010.

The product of its digits is 40000, while the sum is 37.

The square root of 8555581 is about 2924.9924786228. The cubic root of 8555581 is about 204.5266174108.

The spelling of 8555581 in words is "eight million, five hundred fifty-five thousand, five hundred eighty-one".