646320 has 40 divisors (see below), whose sum is σ = 2004336. Its totient is φ = 172288.

The previous prime is 646309. The next prime is 646339. The reversal of 646320 is 23646.

646320 = T₈₅ + T₈₆ + ... + T₁₆₄.

646320 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a tau number, because it is divible by the number of its divisors (40).

It is an unprimeable number.

646320 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, 1107 + ... + 1586.

2⁶⁴⁶³²⁰ is an apocalyptic number.

646320 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

646320 is an abundant number, since it is smaller than the sum of its proper divisors (1358016).

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

646320 is a wasteful number, since it uses less digits than its factorization.

646320 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2709 (or 2703 counting only the distinct ones).

The product of its (nonzero) digits is 864, while the sum is 21.

The square root of 646320 is about 803.9402962907. The cubic root of 646320 is about 86.4601261866.

Adding to 646320 its reverse (23646), we get a palindrome (669966).

The spelling of 646320 in words is "six hundred forty-six thousand, three hundred twenty".