8005581 has 8 divisors (see below), whose sum is σ = 11860160. Its totient is φ = 5337036.

The previous prime is 8005573. The next prime is 8005603. The reversal of 8005581 is 1855008.

8005581 is a `hidden beast` number, since 80 + 0 + 5 + 581 = 666.

It is not a de Polignac number, because 8005581 - 2³ = 8005573 is a prime.

It is a super-2 number, since 2×8005581² = 128178654295122, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (27), and also a Moran number because the ratio is a prime number: 296503 = 8005581 / (8 + 0 + 0 + 5 + 5 + 8 + 1).

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (8005511) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 148225 + ... + 148278.

It is an arithmetic number, because the mean of its divisors is an integer number (1482520).

Almost surely, 2^8005581 is an apocalyptic number.

It is an amenable number.

8005581 is a deficient number, since it is larger than the sum of its proper divisors (3854579).

8005581 is a wasteful number, since it uses less digits than its factorization.

8005581 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 296512 (or 296506 counting only the distinct ones).

The product of its (nonzero) digits is 1600, while the sum is 27.

The square root of 8005581 is about 2829.4135434750. The cubic root of 8005581 is about 200.0464975224.

The spelling of 8005581 in words is "eight million, five thousand, five hundred eighty-one".