647980 has 24 divisors (see below), whose sum is σ = 1375920. Its totient is φ = 256320.

The previous prime is 647963. The next prime is 647987. The reversal of 647980 is 89746.

647980 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a hoax number, since the sum of its digits (34) coincides with the sum of the digits of its distinct prime factors.

It is an Ulam number.

It is a congruent number.

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

647980 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, 3490 + ... + 3670.

It is an arithmetic number, because the mean of its divisors is an integer number (57330).

2⁶⁴⁷⁹⁸⁰ is an apocalyptic number.

It is an amenable number.

647980 is an abundant number, since it is smaller than the sum of its proper divisors (727940).

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

647980 is a wasteful number, since it uses less digits than its factorization.

647980 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 369 (or 367 counting only the distinct ones).

The product of its (nonzero) digits is 12096, while the sum is 34.

The square root of 647980 is about 804.9720492042. The cubic root of 647980 is about 86.5340839318.

The spelling of 647980 in words is "six hundred forty-seven thousand, nine hundred eighty".