39440 has 40 divisors (see below), whose sum is σ = 100440. Its totient is φ = 14336.

The previous prime is 39439. The next prime is 39443. The reversal of 39440 is 4493.

It can be written as a sum of positive squares in 4 ways, for example, as 8464 + 30976 = 92^2 + 176^2 .

It is a tau number, because it is divible by the number of its divisors (40).

It is a Harshad number since it is a multiple of its sum of digits (20).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (39443) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (5) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1346 + ... + 1374.

It is an arithmetic number, because the mean of its divisors is an integer number (2511).

2³⁹⁴⁴⁰ is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 39440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (50220).

39440 is an abundant number, since it is smaller than the sum of its proper divisors (61000).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

39440 is a wasteful number, since it uses less digits than its factorization.

39440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 59 (or 53 counting only the distinct ones).

The product of its (nonzero) digits is 432, while the sum is 20.

The square root of 39440 is about 198.5950653969. The cubic root of 39440 is about 34.0391705416.

It can be divided in two parts, 394 and 40, that added together give a palindrome (434).

The spelling of 39440 in words is "thirty-nine thousand, four hundred forty".