3939 has 8 divisors (see below), whose sum is σ = 5712. Its totient is φ = 2400.

The previous prime is 3931. The next prime is 3943. The reversal of 3939 is 9393.

3939 = 11² + 12² + ... + 23².

3939 is an esthetic number in base 12, because in such base its adjacent digits differ by 1.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 3939 - 2³ = 3931 is a prime.

3939 is an undulating number in base 10.

It is a plaindrome in base 5 and 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 (3931) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 12 + ... + 89.

It is an arithmetic number, because the mean of its divisors is an integer number (714).

2³⁹³⁹ is an apocalyptic number.

3939 is a gapful number since it is divisible by the number (39) formed by its first and last digit.

3939 is a deficient number, since it is larger than the sum of its proper divisors (1773).

3939 is a wasteful number, since it uses less digits than its factorization.

3939 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 117.

The product of its digits is 729, while the sum is 24.

The square root of 3939 is about 62.7614531381. The cubic root of 3939 is about 15.7929039331.

It can be divided in two parts, 39 and 39, that added together give a triangular number (78 = T₁₂).

The spelling of 3939 in words is "three thousand, nine hundred thirty-nine".