9979985 has 16 divisors (see below), whose sum is σ = 12559872.
Its totient is φ = 7611120.
The previous prime is 9979967. The next prime is 9979993. The reversal of 9979985 is 5899799.
It is not a de Polignac number, because 9979985 - 210 = 9978961 is a prime.
It is a Duffinian number.
It is a self number, because there is not a number n which added to its sum of digits gives 9979985.
It is a congruent number.
It is an unprimeable number.
It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 148922 + ... + 148988.
It is an arithmetic number, because the mean of its divisors is an integer number (784992).
Almost surely, 29979985 is an apocalyptic number.
It is an amenable number.
9979985 is a deficient number, since it is larger than the sum of its proper divisors (2579887).
9979985 is an frugal number, since it uses more digits than its factorization.
9979985 is an evil number, because the sum of its binary digits is even.
The sum of its prime factors is 165 (or 103 counting only the distinct ones).
The product of its digits is 1837080, while the sum is 56.
The square root of 9979985 is about 3159.1114257019.
Note that the first 3 decimals coincide.
The cubic root of 9979985 is about 215.2996362990.
The spelling of 9979985 in words is "nine million, nine hundred seventy-nine thousand, nine hundred eighty-five".