3985640 has 32 divisors (see below), whose sum is σ = 9213480. Its totient is φ = 1550592.

The previous prime is 3985637. The next prime is 3985661. The reversal of 3985640 is 465893.

3985640 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 4 ways, for example, as 3678724 + 306916 = 1918^2 + 554^2 .

It is an Ulam number.

It is a self number, because there is not a number n which added to its sum of digits gives 3985640.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 134 + ... + 2826.

Almost surely, 2^3985640 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 3985640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (4606740).

3985640 is an abundant number, since it is smaller than the sum of its proper divisors (5227840).

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

3985640 is a wasteful number, since it uses less digits than its factorization.

3985640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2741 (or 2737 counting only the distinct ones).

The product of its (nonzero) digits is 25920, while the sum is 35.

The square root of 3985640 is about 1996.4067721785. The cubic root of 3985640 is about 158.5499184322.

The spelling of 3985640 in words is "three million, nine hundred eighty-five thousand, six hundred forty".