3985 has 4 divisors (see below), whose sum is σ = 4788.
Its totient is φ = 3184.
The previous prime is 3967. The next prime is 3989. The reversal of 3985 is 5893.
It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 5893 = 71 ⋅83.
It can be written as a sum of positive squares in 2 ways, for example, as 1681 + 2304 = 41^2 + 48^2
It is a cyclic number.
It is a de Polignac number, because none of the positive numbers 2k-3985 is a prime.
It is a Duffinian number.
It is a plaindrome in base 15.
It is a nialpdrome in base 8 and base 16.
It is a congruent number.
It is not an unprimeable number, because it can be changed into a prime (3989) by changing a digit.
It is a pernicious number, because its binary representation contains a prime number (7) of ones.
It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 394 + ... + 403.
It is an arithmetic number, because the mean of its divisors is an integer number (1197).
It is an amenable number.
3985 is a deficient number, since it is larger than the sum of its proper divisors (803).
3985 is an equidigital number, since it uses as much as digits as its factorization.
3985 is an odious number, because the sum of its binary digits is odd.
The sum of its prime factors is 802.
The product of its digits is 1080, while the sum is 25.
The square root of 3985 is about 63.1268564083.
The cubic root of 3985 is about 15.8541431516.
The spelling of 3985 in words is "three thousand, nine hundred eighty-five".