406820 has 12 divisors (see below), whose sum is σ = 854364. Its totient is φ = 162720.

The previous prime is 406817. The next prime is 406837. The reversal of 406820 is 28604.

It can be written as a sum of positive squares in 2 ways, for example, as 200704 + 206116 = 448^2 + 454^2 .

It is a Harshad number since it is a multiple of its sum of digits (20), and also a Moran number because the ratio is a prime number: 20341 = 406820 / (4 + 0 + 6 + 8 + 2 + 0).

It is a junction number, because it is equal to n+sod(n) for n = 406792 and 406801.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 10151 + ... + 10190.

It is an arithmetic number, because the mean of its divisors is an integer number (71197).

2⁴⁰⁶⁸²⁰ is an apocalyptic number.

It is an amenable number.

406820 is an abundant number, since it is smaller than the sum of its proper divisors (447544).

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

406820 is a wasteful number, since it uses less digits than its factorization.

It is an anagram of its base 9 representation: 406820 = (680042)₉.

406820 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20350 (or 20348 counting only the distinct ones).

The product of its (nonzero) digits is 384, while the sum is 20.

The square root of 406820 is about 637.8244272525. The cubic root of 406820 is about 74.0970239382.

The spelling of 406820 in words is "four hundred six thousand, eight hundred twenty".