647988 has 24 divisors (see below), whose sum is σ = 1649760. Its totient is φ = 196320.

The previous prime is 647987. The next prime is 648007. The reversal of 647988 is 889746.

It is a happy number.

647988 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a congruent number.

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 in 7 ways as a sum of consecutive naturals, for example, 2323 + ... + 2586.

It is an arithmetic number, because the mean of its divisors is an integer number (68740).

2⁶⁴⁷⁹⁸⁸ is an apocalyptic number.

It is an amenable number.

647988 is an abundant number, since it is smaller than the sum of its proper divisors (1001772).

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

647988 is a wasteful number, since it uses less digits than its factorization.

647988 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4927 (or 4925 counting only the distinct ones).

The product of its digits is 96768, while the sum is 42.

The square root of 647988 is about 804.9770183055. The cubic root of 647988 is about 86.5344400486.

The spelling of 647988 in words is "six hundred forty-seven thousand, nine hundred eighty-eight".