9985939987 has 4 divisors (see below), whose sum is σ = 9989433216. Its totient is φ = 9982446760.

The previous prime is 9985939979. The next prime is 9985940021. The reversal of 9985939987 is 7899395899.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 9985939987 - 2³ = 9985939979 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (9985939967) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1742323 + ... + 1748044.

It is an arithmetic number, because the mean of its divisors is an integer number (2497358304).

Almost surely, 2^9985939987 is an apocalyptic number.

9985939987 is a deficient number, since it is larger than the sum of its proper divisors (3493229).

9985939987 is a wasteful number, since it uses less digits than its factorization.

9985939987 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3493228.

The product of its digits is 396809280, while the sum is 76.

The square root of 9985939987 is about 99929.6752071175. The cubic root of 9985939987 is about 2153.4245037845.

The spelling of 9985939987 in words is "nine billion, nine hundred eighty-five million, nine hundred thirty-nine thousand, nine hundred eighty-seven".