9899999987 has 2 divisors, whose sum is σ = 9899999988. Its totient is φ = 9899999986.

The previous prime is 9899999971. The next prime is 9900000001. The reversal of 9899999987 is 7899999989.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 9899999987 - 2⁴ = 9899999971 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 9899999899 and 9899999908.

It is not a weakly prime, because it can be changed into another prime (9899999957) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4949999993 + 4949999994.

It is an arithmetic number, because the mean of its divisors is an integer number (4949999994).

Almost surely, 2^9899999987 is an apocalyptic number.

9899999987 is a deficient number, since it is larger than the sum of its proper divisors (1).

9899999987 is an equidigital number, since it uses as much as digits as its factorization.

9899999987 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2142770112, while the sum is 86.

The square root of 9899999987 is about 99498.7436453345. The cubic root of 9899999987 is about 2147.2291680791.

The spelling of 9899999987 in words is "nine billion, eight hundred ninety-nine million, nine hundred ninety-nine thousand, nine hundred eighty-seven".