8397607781 has 2 divisors, whose sum is σ = 8397607782. Its totient is φ = 8397607780.

The previous prime is 8397607711. The next prime is 8397607789. The reversal of 8397607781 is 1877067938.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 8352314881 + 45292900 = 91391^2 + 6730^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-8397607781 is a prime.

It is a super-2 number, since 2×8397607781² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (8397607789) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4198803890 + 4198803891.

It is an arithmetic number, because the mean of its divisors is an integer number (4198803891).

Almost surely, 2^8397607781 is an apocalyptic number.

It is an amenable number.

8397607781 is a deficient number, since it is larger than the sum of its proper divisors (1).

8397607781 is an equidigital number, since it uses as much as digits as its factorization.

8397607781 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 3556224, while the sum is 56.

The square root of 8397607781 is about 91638.4623452402. The cubic root of 8397607781 is about 2032.5997236672.

The spelling of 8397607781 in words is "eight billion, three hundred ninety-seven million, six hundred seven thousand, seven hundred eighty-one".