6409728 has 120 divisors (see below), whose sum is σ = 20108088. Its totient is φ = 1953792.

The previous prime is 6409721. The next prime is 6409747. The reversal of 6409728 is 8279046.

6409728 is a `hidden beast` number, since 640 + 9 + 7 + 2 + 8 = 666.

It is a super-2 number, since 2×6409728² = 82169226067968, which contains 22 as substring.

It is a Smith number, since the sum of its digits (36) coincides with the sum of the digits of its prime factors.

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

It is a zygodrome in base 2 and base 3.

It is a junction number, because it is equal to n+sod(n) for n = 6409692 and 6409701.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6409721) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 59851 + ... + 59957.

Almost surely, 2^6409728 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 6409728, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (10054044).

6409728 is an abundant number, since it is smaller than the sum of its proper divisors (13698360).

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

6409728 is a wasteful number, since it uses less digits than its factorization.

6409728 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 144 (or 125 counting only the distinct ones).

The product of its (nonzero) digits is 24192, while the sum is 36.

The square root of 6409728 is about 2531.7440628942. The cubic root of 6409728 is about 185.7575752565.

The spelling of 6409728 in words is "six million, four hundred nine thousand, seven hundred twenty-eight".