9909671987 has 2 divisors, whose sum is σ = 9909671988. Its totient is φ = 9909671986.

The previous prime is 9909671957. The next prime is 9909672007. The reversal of 9909671987 is 7891769099.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 9909671987 - 2¹⁰ = 9909670963 is a prime.

It is not a weakly prime, because it can be changed into another prime (9909671957) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4954835993 + 4954835994.

It is an arithmetic number, because the mean of its divisors is an integer number (4954835994).

Almost surely, 2^9909671987 is an apocalyptic number.

9909671987 is a deficient number, since it is larger than the sum of its proper divisors (1).

9909671987 is an equidigital number, since it uses as much as digits as its factorization.

9909671987 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 15431472, while the sum is 65.

The square root of 9909671987 is about 99547.3354088395. The cubic root of 9909671987 is about 2147.9281997617.

The spelling of 9909671987 in words is "nine billion, nine hundred nine million, six hundred seventy-one thousand, nine hundred eighty-seven".