8165681 has 2 divisors, whose sum is σ = 8165682. Its totient is φ = 8165680.

The previous prime is 8165671. The next prime is 8165701. The reversal of 8165681 is 1865618.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 4165681 + 4000000 = 2041^2 + 2000^2 .

It is a cyclic number.

It is not a de Polignac number, because 8165681 - 2¹⁰ = 8164657 is a prime.

It is a super-2 number, since 2×8165681² = 133356692387522, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (8165671) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4082840 + 4082841.

It is an arithmetic number, because the mean of its divisors is an integer number (4082841).

Almost surely, 2^8165681 is an apocalyptic number.

It is an amenable number.

8165681 is a deficient number, since it is larger than the sum of its proper divisors (1).

8165681 is an equidigital number, since it uses as much as digits as its factorization.

8165681 is an evil number, because the sum of its binary digits is even.

The product of its digits is 11520, while the sum is 35.

The square root of 8165681 is about 2857.5655723010. The cubic root of 8165681 is about 201.3712518550.

The spelling of 8165681 in words is "eight million, one hundred sixty-five thousand, six hundred eighty-one".