39639 has 8 divisors (see below), whose sum is σ = 53872. Its totient is φ = 25920.

The previous prime is 39631. The next prime is 39659. The reversal of 39639 is 93693.

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

It is not a de Polignac number, because 39639 - 2³ = 39631 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (39631) 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, 129 + ... + 309.

It is an arithmetic number, because the mean of its divisors is an integer number (6734).

2³⁹⁶³⁹ is an apocalyptic number.

39639 is a deficient number, since it is larger than the sum of its proper divisors (14233).

39639 is a wasteful number, since it uses less digits than its factorization.

39639 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 257.

The product of its digits is 4374, while the sum is 30.

The square root of 39639 is about 199.0954544936. The cubic root of 39639 is about 34.0963243115.

It can be divided in two parts, 396 and 39, that added together give a triangular number (435 = T₂₉).

The spelling of 39639 in words is "thirty-nine thousand, six hundred thirty-nine".