99993987 has 16 divisors (see below), whose sum is σ = 150936480. Its totient is φ = 65403936.

The previous prime is 99993947. The next prime is 99993991. The reversal of 99993987 is 78939999.

It is not a de Polignac number, because 99993987 - 2⁶ = 99993923 is a prime.

It is not an unprimeable number, because it can be changed into a prime (99993917) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 33508 + ... + 36369.

It is an arithmetic number, because the mean of its divisors is an integer number (9433530).

Almost surely, 2^99993987 is an apocalyptic number.

99993987 is a deficient number, since it is larger than the sum of its proper divisors (50942493).

99993987 is a wasteful number, since it uses less digits than its factorization.

99993987 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 69939 (or 69933 counting only the distinct ones).

The product of its digits is 9920232, while the sum is 63.

The square root of 99993987 is about 9999.6993454803. The cubic root of 99993987 is about 464.1495798836.

The spelling of 99993987 in words is "ninety-nine million, nine hundred ninety-three thousand, nine hundred eighty-seven".