646980 has 48 divisors (see below), whose sum is σ = 1862784. Its totient is φ = 167680.

The previous prime is 646979. The next prime is 646981. The reversal of 646980 is 89646.

It is an interprime number because it is at equal distance from previous prime (646979) and next prime (646981).

It is a nialpdrome in base 15.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 646980.

It is not an unprimeable number, because it can be changed into a prime (646981) 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 15 ways as a sum of consecutive naturals, for example, 2329 + ... + 2591.

It is an arithmetic number, because the mean of its divisors is an integer number (38808).

2⁶⁴⁶⁹⁸⁰ is an apocalyptic number.

646980 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 646980, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (931392).

646980 is an abundant number, since it is smaller than the sum of its proper divisors (1215804).

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

646980 is a wasteful number, since it uses less digits than its factorization.

646980 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 316 (or 314 counting only the distinct ones).

The product of its (nonzero) digits is 10368, while the sum is 33.

The square root of 646980 is about 804.3506697952. The cubic root of 646980 is about 86.4895462213.

The spelling of 646980 in words is "six hundred forty-six thousand, nine hundred eighty".