8005681 has 2 divisors, whose sum is σ = 8005682. Its totient is φ = 8005680.

The previous prime is 8005667. The next prime is 8005693. The reversal of 8005681 is 1865008.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 7750656 + 255025 = 2784^2 + 505^2 .

It is a cyclic number.

It is not a de Polignac number, because 8005681 - 2⁵ = 8005649 is a prime.

It is a super-2 number, since 2×8005681² = 128181856547522, which contains 22 as substring.

It is an Ulam number.

It is not a weakly prime, because it can be changed into another prime (8305681) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4002840 + 4002841.

It is an arithmetic number, because the mean of its divisors is an integer number (4002841).

Almost surely, 2^8005681 is an apocalyptic number.

It is an amenable number.

8005681 is a deficient number, since it is larger than the sum of its proper divisors (1).

8005681 is an equidigital number, since it uses as much as digits as its factorization.

8005681 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1920, while the sum is 28.

The square root of 8005681 is about 2829.4312149264. The cubic root of 8005681 is about 200.0473304649.

The spelling of 8005681 in words is "eight million, five thousand, six hundred eighty-one".