8172257689 has 2 divisors, whose sum is σ = 8172257690. Its totient is φ = 8172257688.

The previous prime is 8172257641. The next prime is 8172257693. The reversal of 8172257689 is 9867522718.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 6873736464 + 1298521225 = 82908^2 + 36035^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-8172257689 is a prime.

It is not a weakly prime, because it can be changed into another prime (8172257609) 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, 4086128844 + 4086128845.

It is an arithmetic number, because the mean of its divisors is an integer number (4086128845).

Almost surely, 2^8172257689 is an apocalyptic number.

It is an amenable number.

8172257689 is a deficient number, since it is larger than the sum of its proper divisors (1).

8172257689 is an equidigital number, since it uses as much as digits as its factorization.

8172257689 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 3386880, while the sum is 55.

The square root of 8172257689 is about 90400.5403136508. The cubic root of 8172257689 is about 2014.2529922342.

The spelling of 8172257689 in words is "eight billion, one hundred seventy-two million, two hundred fifty-seven thousand, six hundred eighty-nine".