20208820 has 24 divisors (see below), whose sum is σ = 42525000. Its totient is φ = 8067072.

The previous prime is 20208817. The next prime is 20208821. The reversal of 20208820 is 2880202.

It can be written as a sum of positive squares in 4 ways, for example, as 4511376 + 15697444 = 2124^2 + 3962^2 .

It is a junction number, because it is equal to n+sod(n) for n = 20208791 and 20208800.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20208821) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 15556 + ... + 16804.

It is an arithmetic number, because the mean of its divisors is an integer number (1771875).

Almost surely, 2^20208820 is an apocalyptic number.

20208820 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20208820 is an abundant number, since it is smaller than the sum of its proper divisors (22316180).

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

20208820 is a wasteful number, since it uses less digits than its factorization.

20208820 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2067 (or 2065 counting only the distinct ones).

The product of its (nonzero) digits is 512, while the sum is 22.

The square root of 20208820 is about 4495.4221158863. The cubic root of 20208820 is about 272.3832005125.

The spelling of 20208820 in words is "twenty million, two hundred eight thousand, eight hundred twenty".