8340781 has 2 divisors, whose sum is σ = 8340782. Its totient is φ = 8340780.

The previous prime is 8340749. The next prime is 8340793. The reversal of 8340781 is 1870438.

It is a happy number.

8340781 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 7645225 + 695556 = 2765^2 + 834^2 .

It is a cyclic number.

It is not a de Polignac number, because 8340781 - 2⁵ = 8340749 is a prime.

It is a super-2 number, since 2×8340781² = 139137255379922, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (8340721) by changing a digit.

It is a good prime.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4170390 + 4170391.

It is an arithmetic number, because the mean of its divisors is an integer number (4170391).

Almost surely, 2^8340781 is an apocalyptic number.

It is an amenable number.

8340781 is a deficient number, since it is larger than the sum of its proper divisors (1).

8340781 is an equidigital number, since it uses as much as digits as its factorization.

8340781 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 5376, while the sum is 31.

The square root of 8340781 is about 2888.0410315645. The cubic root of 8340781 is about 202.8004461526.

The spelling of 8340781 in words is "eight million, three hundred forty thousand, seven hundred eighty-one".