647668 has 12 divisors (see below), whose sum is σ = 1295392. Its totient is φ = 277560.

The previous prime is 647663. The next prime is 647687. The reversal of 647668 is 866746.

647668 is an admirable number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (647663) by changing a digit.

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 3 ways as a sum of consecutive naturals, for example, 11538 + ... + 11593.

2⁶⁴⁷⁶⁶⁸ is an apocalyptic number.

It is an amenable number.

647668 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

647668 is a wasteful number, since it uses less digits than its factorization.

647668 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 23142 (or 23140 counting only the distinct ones).

The product of its digits is 48384, while the sum is 37.

The square root of 647668 is about 804.7782303219. The cubic root of 647668 is about 86.5201930871.

It can be divided in two parts, 6 and 47668, that added together give a palindrome (47674).

The spelling of 647668 in words is "six hundred forty-seven thousand, six hundred sixty-eight".