6420728 has 16 divisors (see below), whose sum is σ = 12065760. Its totient is φ = 3203200.

The previous prime is 6420709. The next prime is 6420731. The reversal of 6420728 is 8270246.

It is a zygodrome in base 2.

It is a self number, because there is not a number n which added to its sum of digits gives 6420728.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6593 + ... + 7503.

It is an arithmetic number, because the mean of its divisors is an integer number (754110).

Almost surely, 2^6420728 is an apocalyptic number.

It is an amenable number.

6420728 is a deficient number, since it is larger than the sum of its proper divisors (5645032).

6420728 is a wasteful number, since it uses less digits than its factorization.

6420728 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1798 (or 1794 counting only the distinct ones).

The product of its (nonzero) digits is 5376, while the sum is 29.

The square root of 6420728 is about 2533.9155471325. The cubic root of 6420728 is about 185.8637766199.

The spelling of 6420728 in words is "six million, four hundred twenty thousand, seven hundred twenty-eight".