99987869 has 2 divisors, whose sum is σ = 99987870. Its totient is φ = 99987868.

The previous prime is 99987817. The next prime is 99987871. The reversal of 99987869 is 96878999.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 95785369 + 4202500 = 9787^2 + 2050^2 .

It is a cyclic number.

It is not a de Polignac number, because 99987869 - 2²⁰ = 98939293 is a prime.

It is a super-2 number, since 2×99987869² = 19995147894322322, which contains 22 as substring.

It is a Sophie Germain prime.

Together with 99987871, it forms a pair of twin primes.

It is a Chen prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (99987269) 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, 49993934 + 49993935.

It is an arithmetic number, because the mean of its divisors is an integer number (49993935).

Almost surely, 2^99987869 is an apocalyptic number.

It is an amenable number.

99987869 is a deficient number, since it is larger than the sum of its proper divisors (1).

99987869 is an equidigital number, since it uses as much as digits as its factorization.

99987869 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 17635968, while the sum is 65.

The square root of 99987869 is about 9999.3934316037. The cubic root of 99987869 is about 464.1401135642.

The spelling of 99987869 in words is "ninety-nine million, nine hundred eighty-seven thousand, eight hundred sixty-nine".