8081581 has 2 divisors, whose sum is σ = 8081582. Its totient is φ = 8081580.

The previous prime is 8081573. The next prime is 8081629. The reversal of 8081581 is 1851808.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 7209225 + 872356 = 2685^2 + 934^2 .

It is a cyclic number.

It is not a de Polignac number, because 8081581 - 2³ = 8081573 is a prime.

It is a super-2 number, since 2×8081581² = 130623902919122, which contains 22 as substring.

It is a nialpdrome in base 15.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (8081501) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4040790 + 4040791.

It is an arithmetic number, because the mean of its divisors is an integer number (4040791).

Almost surely, 2^8081581 is an apocalyptic number.

It is an amenable number.

8081581 is a deficient number, since it is larger than the sum of its proper divisors (1).

8081581 is an equidigital number, since it uses as much as digits as its factorization.

8081581 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2560, while the sum is 31.

The square root of 8081581 is about 2842.8121640376. The cubic root of 8081581 is about 200.6775437470.

The spelling of 8081581 in words is "eight million, eighty-one thousand, five hundred eighty-one".