1005581 has 2 divisors, whose sum is σ = 1005582. Its totient is φ = 1005580.

The previous prime is 1005553. The next prime is 1005593. The reversal of 1005581 is 1855001.

1005581 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 872356 + 133225 = 934^2 + 365^2 .

It is an emirp because it is prime and its reverse (1855001) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1005581 is a prime.

It is a super-2 number, since 2×1005581² = 2022386295122, which contains 22 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1005541) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 502790 + 502791.

It is an arithmetic number, because the mean of its divisors is an integer number (502791).

2^1005581 is an apocalyptic number.

It is an amenable number.

1005581 is a deficient number, since it is larger than the sum of its proper divisors (1).

1005581 is an equidigital number, since it uses as much as digits as its factorization.

1005581 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 200, while the sum is 20.

The square root of 1005581 is about 1002.7866173818. The cubic root of 1005581 is about 100.1856883184.

The spelling of 1005581 in words is "one million, five thousand, five hundred eighty-one".