647940 has 24 divisors (see below), whose sum is σ = 1814400. Its totient is φ = 172768.

The previous prime is 647917. The next prime is 647951. The reversal of 647940 is 49746.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a junction number, because it is equal to n+sod(n) for n = 647898 and 647907.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 647940.

It is an unprimeable number.

647940 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, 5340 + ... + 5459.

It is an arithmetic number, because the mean of its divisors is an integer number (75600).

2⁶⁴⁷⁹⁴⁰ is an apocalyptic number.

647940 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

647940 is an abundant number, since it is smaller than the sum of its proper divisors (1166460).

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

647940 is a wasteful number, since it uses less digits than its factorization.

647940 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10811 (or 10809 counting only the distinct ones).

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

The square root of 647940 is about 804.9472032376. The cubic root of 647940 is about 86.5323033035.

The spelling of 647940 in words is "six hundred forty-seven thousand, nine hundred forty".