646220 has 24 divisors (see below), whose sum is σ = 1377600. Its totient is φ = 254592.

The previous prime is 646199. The next prime is 646237. The reversal of 646220 is 22646.

646220 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a Harshad number since it is a multiple of its sum of digits (20).

It is a junction number, because it is equal to n+sod(n) for n = 646192 and 646201.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 646220.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1376 + ... + 1784.

It is an arithmetic number, because the mean of its divisors is an integer number (57400).

2⁶⁴⁶²²⁰ is an apocalyptic number.

It is an amenable number.

646220 is an abundant number, since it is smaller than the sum of its proper divisors (731380).

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

646220 is a wasteful number, since it uses less digits than its factorization.

646220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 497 (or 495 counting only the distinct ones).

The product of its (nonzero) digits is 576, while the sum is 20.

The square root of 646220 is about 803.8781002117. The cubic root of 646220 is about 86.4556668586.

Adding to 646220 its reverse (22646), we get a palindrome (668866).

The spelling of 646220 in words is "six hundred forty-six thousand, two hundred twenty".