9987891269 has 2 divisors, whose sum is σ = 9987891270. Its totient is φ = 9987891268.

The previous prime is 9987891239. The next prime is 9987891281. The reversal of 9987891269 is 9621987899.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 9466317025 + 521574244 = 97295^2 + 22838^2 .

It is a cyclic number.

It is not a de Polignac number, because 9987891269 - 2²⁰ = 9986842693 is a prime.

It is a super-2 number, since 2×9987891269² (a number of 21 digits) contains 22 as substring.

It is a Sophie Germain prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 9987891199 and 9987891208.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (9987891229) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4993945634 + 4993945635.

It is an arithmetic number, because the mean of its divisors is an integer number (4993945635).

Almost surely, 2^9987891269 is an apocalyptic number.

It is an amenable number.

9987891269 is a deficient number, since it is larger than the sum of its proper divisors (1).

9987891269 is an equidigital number, since it uses as much as digits as its factorization.

9987891269 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 35271936, while the sum is 68.

The square root of 9987891269 is about 99939.4380062245. The cubic root of 9987891269 is about 2153.5647564737.

The spelling of 9987891269 in words is "nine billion, nine hundred eighty-seven million, eight hundred ninety-one thousand, two hundred sixty-nine".