647904 has 48 divisors (see below), whose sum is σ = 1805328. Its totient is φ = 202752.

The previous prime is 647893. The next prime is 647909. The reversal of 647904 is 409746.

It is a tau number, because it is divible by the number of its divisors (48).

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 647904.

It is not an unprimeable number, because it can be changed into a prime (647909) by changing a digit.

647904 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1434 + ... + 1830.

It is an arithmetic number, because the mean of its divisors is an integer number (37611).

2⁶⁴⁷⁹⁰⁴ 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 647904, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (902664).

647904 is an abundant number, since it is smaller than the sum of its proper divisors (1157424).

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

647904 is a wasteful number, since it uses less digits than its factorization.

647904 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 427 (or 419 counting only the distinct ones).

The product of its (nonzero) digits is 6048, while the sum is 30.

The square root of 647904 is about 804.9248412119. The cubic root of 647904 is about 86.5307006753.

It can be divided in two parts, 647 and 904, that added together give a palindrome (1551).

The spelling of 647904 in words is "six hundred forty-seven thousand, nine hundred four".