6403968 has 128 divisors (see below), whose sum is σ = 20196000. Its totient is φ = 1990656.

The previous prime is 6403967. The next prime is 6403973. The reversal of 6403968 is 8693046.

6403968 is a `hidden beast` number, since 640 + 3 + 9 + 6 + 8 = 666.

It is a tau number, because it is divible by the number of its divisors (128).

It is a super-2 number, since 2×6403968² = 82021612290048, which contains 22 as substring.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6403967) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 58698 + ... + 58806.

Almost surely, 2^6403968 is an apocalyptic number.

6403968 is a gapful number since it is divisible by the number (68) 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 6403968, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (10098000).

6403968 is an abundant number, since it is smaller than the sum of its proper divisors (13792032).

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

6403968 is a wasteful number, since it uses less digits than its factorization.

6403968 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 149 (or 131 counting only the distinct ones).

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

The square root of 6403968 is about 2530.6062514741. The cubic root of 6403968 is about 185.7019158850.

The spelling of 6403968 in words is "six million, four hundred three thousand, nine hundred sixty-eight".