3639 has 4 divisors (see below), whose sum is σ = 4856. Its totient is φ = 2424.

The previous prime is 3637. The next prime is 3643. The reversal of 3639 is 9363.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 9363 = 3 ⋅3121.

It is not a de Polignac number, because 3639 - 2¹ = 3637 is a prime.

It is a D-number.

It is a Duffinian number.

It is a plaindrome in base 14 and base 15.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (3631) 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, 604 + ... + 609.

It is an arithmetic number, because the mean of its divisors is an integer number (1214).

3639 is a deficient number, since it is larger than the sum of its proper divisors (1217).

3639 is a wasteful number, since it uses less digits than its factorization.

3639 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1216.

The product of its digits is 486, while the sum is 21.

The square root of 3639 is about 60.3241245274. The cubic root of 3639 is about 15.3813345568.

The spelling of 3639 in words is "three thousand, six hundred thirty-nine".