8159681 has 2 divisors, whose sum is σ = 8159682. Its totient is φ = 8159680.

The previous prime is 8159663. The next prime is 8159731. The reversal of 8159681 is 1869518.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 7612081 + 547600 = 2759^2 + 740^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-8159681 is a prime.

It is a super-2 number, since 2×8159681² = 133160788043522, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (8159611) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4079840 + 4079841.

It is an arithmetic number, because the mean of its divisors is an integer number (4079841).

Almost surely, 2^8159681 is an apocalyptic number.

It is an amenable number.

8159681 is a deficient number, since it is larger than the sum of its proper divisors (1).

8159681 is an equidigital number, since it uses as much as digits as its factorization.

8159681 is an evil number, because the sum of its binary digits is even.

The product of its digits is 17280, while the sum is 38.

The square root of 8159681 is about 2856.5155347031. The cubic root of 8159681 is about 201.3219184085.

The spelling of 8159681 in words is "eight million, one hundred fifty-nine thousand, six hundred eighty-one".