8065781 has 2 divisors, whose sum is σ = 8065782. Its totient is φ = 8065780.

The previous prime is 8065777. The next prime is 8065789. The reversal of 8065781 is 1875608.

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., 8031556 + 34225 = 2834^2 + 185^2 .

It is a cyclic number.

It is not a de Polignac number, because 8065781 - 2² = 8065777 is a prime.

It is a super-2 number, since 2×8065781² = 130113646279922, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (8065789) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4032890 + 4032891.

It is an arithmetic number, because the mean of its divisors is an integer number (4032891).

Almost surely, 2^8065781 is an apocalyptic number.

It is an amenable number.

8065781 is a deficient number, since it is larger than the sum of its proper divisors (1).

8065781 is an equidigital number, since it uses as much as digits as its factorization.

8065781 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 13440, while the sum is 35.

The square root of 8065781 is about 2840.0318660184. The cubic root of 8065781 is about 200.5466793470.

The spelling of 8065781 in words is "eight million, sixty-five thousand, seven hundred eighty-one".