3997440 has 108 divisors (see below), whose sum is σ = 13870584. Its totient is φ = 1062912.

The previous prime is 3997403. The next prime is 3997453. The reversal of 3997440 is 447993.

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

It is an Ulam number.

It is a zygodrome in base 2.

It is a junction number, because it is equal to n+sod(n) for n = 3997395 and 3997404.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 11347 + ... + 11693.

Almost surely, 2^3997440 is an apocalyptic number.

3997440 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 3997440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (6935292).

3997440 is an abundant number, since it is smaller than the sum of its proper divisors (9873144).

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

3997440 is a wasteful number, since it uses less digits than its factorization.

3997440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 374 (or 357 counting only the distinct ones).

The product of its (nonzero) digits is 27216, while the sum is 36.

The square root of 3997440 is about 1999.3598975672. The cubic root of 3997440 is about 158.7062334140.

It can be divided in two parts, 39 and 97440, that added together give a palindrome (97479).

The spelling of 3997440 in words is "three million, nine hundred ninety-seven thousand, four hundred forty".