3998720 has 88 divisors (see below), whose sum is σ = 10611648. Its totient is φ = 1433600.

The previous prime is 3998719. The next prime is 3998737. The reversal of 3998720 is 278993.

It is a tau number, because it is divible by the number of its divisors (88).

It is an Ulam number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 56285 + ... + 56355.

Almost surely, 2^3998720 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 3998720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (5305824).

3998720 is an abundant number, since it is smaller than the sum of its proper divisors (6612928).

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

3998720 is a wasteful number, since it uses less digits than its factorization.

3998720 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 107 (or 89 counting only the distinct ones).

The product of its (nonzero) digits is 27216, while the sum is 38.

The square root of 3998720 is about 1999.6799743959. The cubic root of 3998720 is about 158.7231711125.

It can be divided in two parts, 399 and 8720, that added together give a palindrome (9119).

The spelling of 3998720 in words is "three million, nine hundred ninety-eight thousand, seven hundred twenty".