8351689681 has 2 divisors, whose sum is σ = 8351689682. Its totient is φ = 8351689680.

The previous prime is 8351689673. The next prime is 8351689789. The reversal of 8351689681 is 1869861538.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 5519747025 + 2831942656 = 74295^2 + 53216^2 .

It is a cyclic number.

It is not a de Polignac number, because 8351689681 - 2³ = 8351689673 is a prime.

It is a super-2 number, since 2×8351689681² (a number of 21 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (8351689631) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4175844840 + 4175844841.

It is an arithmetic number, because the mean of its divisors is an integer number (4175844841).

Almost surely, 2^8351689681 is an apocalyptic number.

It is an amenable number.

8351689681 is a deficient number, since it is larger than the sum of its proper divisors (1).

8351689681 is an equidigital number, since it uses as much as digits as its factorization.

8351689681 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2488320, while the sum is 55.

The square root of 8351689681 is about 91387.5794678905. The cubic root of 8351689681 is about 2028.8882003555. Note that the first 3 decimals are identical.

The spelling of 8351689681 in words is "eight billion, three hundred fifty-one million, six hundred eighty-nine thousand, six hundred eighty-one".