9999987 has 16 divisors (see below), whose sum is σ = 13733280. Its totient is φ = 6469632.

The previous prime is 9999973. The next prime is 9999991. The reversal of 9999987 is 7899999.

9999987 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 9999987 - 2⁴ = 9999971 is a prime.

It is a nialpdrome in base 10.

It is a self number, because there is not a number n which added to its sum of digits gives 9999987.

It is not an unprimeable number, because it can be changed into a prime (9999907) 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, 17043 + ... + 17619.

It is an arithmetic number, because the mean of its divisors is an integer number (858330).

Almost surely, 2^9999987 is an apocalyptic number.

9999987 is a deficient number, since it is larger than the sum of its proper divisors (3733293).

9999987 is a wasteful number, since it uses less digits than its factorization.

9999987 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 742.

The product of its digits is 3306744, while the sum is 60.

The square root of 9999987 is about 3162.2756046872. The cubic root of 9999987 is about 215.4433756443.

The spelling of 9999987 in words is "nine million, nine hundred ninety-nine thousand, nine hundred eighty-seven".