647984 has 10 divisors (see below), whose sum is σ = 1255500. Its totient is φ = 323984.

The previous prime is 647963. The next prime is 647987. The reversal of 647984 is 489746.

It is a happy number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 647984.

It is not an unprimeable number, because it can be changed into a prime (647987) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 20234 + ... + 20265.

It is an arithmetic number, because the mean of its divisors is an integer number (125550).

2⁶⁴⁷⁹⁸⁴ is an apocalyptic number.

It is an amenable number.

647984 is a deficient number, since it is larger than the sum of its proper divisors (607516).

647984 is a wasteful number, since it uses less digits than its factorization.

647984 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 40507 (or 40501 counting only the distinct ones).

The product of its digits is 48384, while the sum is 38.

The square root of 647984 is about 804.9745337587. The cubic root of 647984 is about 86.5342619906.

The spelling of 647984 in words is "six hundred forty-seven thousand, nine hundred eighty-four".