3989 has 2 divisors, whose sum is σ = 3990.
Its totient is φ = 3988.
The previous prime is 3967. The next prime is 4001. The reversal of 3989 is 9893.
It is a strong prime.
It can be written as a sum of positive squares in only one way, i.e., 3364 + 625 = 58^2 + 25^2
It is a cyclic number.
It is not a de Polignac number, because 3989 - 28 = 3733 is a prime.
It is a Chen prime.
It is a plaindrome in base 15.
It is a nialpdrome in base 4, base 9 and base 16.
It is a congruent number.
It is not a weakly prime, because it can be changed into another prime (3919) by changing a digit.
It is a good prime.
It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1994 + 1995.
It is an arithmetic number, because the mean of its divisors is an integer number (1995).
23989 is an apocalyptic number.
It is an amenable number.
3989 is a deficient number, since it is larger than the sum of its proper divisors (1).
3989 is an equidigital number, since it uses as much as digits as its factorization.
3989 is an evil number, because the sum of its binary digits is even.
The product of its digits is 1944, while the sum is 29.
The square root of 3989 is about 63.1585306986.
The cubic root of 3989 is about 15.8594459844.
It can be divided in two parts, 39 and 89, that added together give a 7-th power (128 = 27).
The spelling of 3989 in words is "three thousand, nine hundred eighty-nine".