3968640 has 192 divisors, whose sum is σ = 15036840. Its totient is φ = 958464.

The previous prime is 3968617. The next prime is 3968647. The reversal of 3968640 is 468693.

3968640 is a `hidden beast` number, since 3 + 9 + 6 + 8 + 640 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 2903616 + 1065024 = 1704^2 + 1032^2 .

It is a tau number, because it is divible by the number of its divisors (192).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 3968595 and 3968604.

It is not an unprimeable number, because it can be changed into a prime (3968647) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 74854 + ... + 74906.

Almost surely, 2^3968640 is an apocalyptic number.

3968640 is a gapful number since it is divisible by the number (30) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 3968640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (7518420).

3968640 is an abundant number, since it is smaller than the sum of its proper divisors (11068200).

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

3968640 is a wasteful number, since it uses less digits than its factorization.

3968640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 91 (or 76 counting only the distinct ones).

The product of its (nonzero) digits is 31104, while the sum is 36.

The square root of 3968640 is about 1992.1445730669. The cubic root of 3968640 is about 158.3241755245.

The spelling of 3968640 in words is "three million, nine hundred sixty-eight thousand, six hundred forty".