647928 has 24 divisors (see below), whose sum is σ = 1755000. Its totient is φ = 215952.

The previous prime is 647917. The next prime is 647951. The reversal of 647928 is 829746.

647928 is a `hidden beast` number, since 647 + 9 + 2 + 8 = 666.

It is a tau number, because it is divible by the number of its divisors (24).

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

It is a junction number, because it is equal to n+sod(n) for n = 647892 and 647901.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 647928.

It is an unprimeable number.

647928 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 4428 + ... + 4571.

It is an arithmetic number, because the mean of its divisors is an integer number (73125).

2⁶⁴⁷⁹²⁸ is an apocalyptic number.

It is an amenable number.

647928 is an abundant number, since it is smaller than the sum of its proper divisors (1107072).

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

647928 is a wasteful number, since it uses less digits than its factorization.

647928 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9011 (or 9004 counting only the distinct ones).

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

The square root of 647928 is about 804.9397492980. The cubic root of 647928 is about 86.5317691007.

The spelling of 647928 in words is "six hundred forty-seven thousand, nine hundred twenty-eight".