206404020 has 72 divisors (see below), whose sum is σ = 647697960. Its totient is φ = 53141760.

The previous prime is 206403997. The next prime is 206404027. The reversal of 206404020 is 20404602.

206404020 is a `hidden beast` number, since 2 + 0 + 640 + 4 + 0 + 20 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 79524 + 206324496 = 282^2 + 14364^2 .

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a junction number, because it is equal to n+sod(n) for n = 206403984 and 206404002.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (206404027) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 14551 + ... + 24990.

It is an arithmetic number, because the mean of its divisors is an integer number (8995805).

Almost surely, 2^206404020 is an apocalyptic number.

206404020 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

206404020 is an abundant number, since it is smaller than the sum of its proper divisors (441293940).

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

206404020 is a wasteful number, since it uses less digits than its factorization.

206404020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 39585 (or 39580 counting only the distinct ones).

The product of its (nonzero) digits is 384, while the sum is 18.

The square root of 206404020 is about 14366.7679037423. The cubic root of 206404020 is about 590.9799094753.

Adding to 206404020 its reverse (20404602), we get a palindrome (226808622).

The spelling of 206404020 in words is "two hundred six million, four hundred four thousand, twenty".