7971867989 has 2 divisors, whose sum is σ = 7971867990. Its totient is φ = 7971867988.

The previous prime is 7971867979. The next prime is 7971868007. The reversal of 7971867989 is 9897681797.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 4024887364 + 3946980625 = 63442^2 + 62825^2 .

It is an emirp because it is prime and its reverse (9897681797) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 7971867989 - 2¹⁶ = 7971802453 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (7971867949) 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, 3985933994 + 3985933995.

It is an arithmetic number, because the mean of its divisors is an integer number (3985933995).

Almost surely, 2^7971867989 is an apocalyptic number.

It is an amenable number.

7971867989 is a deficient number, since it is larger than the sum of its proper divisors (1).

7971867989 is an equidigital number, since it uses as much as digits as its factorization.

7971867989 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 96018048, while the sum is 71.

The square root of 7971867989 is about 89285.3178803772. The cubic root of 7971867989 is about 1997.6529124174.

The spelling of 7971867989 in words is "seven billion, nine hundred seventy-one million, eight hundred sixty-seven thousand, nine hundred eighty-nine".