6397440 has 240 divisors, whose sum is σ = 25190352. Its totient is φ = 1376256.

The previous prime is 6397421. The next prime is 6397451. The reversal of 6397440 is 447936.

6397440 is digitally balanced in base 5, because in such base it contains all the possibile digits an equal number of times.

It is a tau number, because it is divible by the number of its divisors (240).

It is a zygodrome in base 2.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 376312 + ... + 376328.

Almost surely, 2^6397440 is an apocalyptic number.

6397440 is a gapful number since it is divisible by the number (60) 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 6397440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (12595176).

6397440 is an abundant number, since it is smaller than the sum of its proper divisors (18792912).

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

6397440 is a wasteful number, since it uses less digits than its factorization.

6397440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 57 (or 34 counting only the distinct ones).

The product of its (nonzero) digits is 18144, while the sum is 33.

The square root of 6397440 is about 2529.3161131025. The cubic root of 6397440 is about 185.6387949026.

The spelling of 6397440 in words is "six million, three hundred ninety-seven thousand, four hundred forty".