20130820 has 48 divisors (see below), whose sum is σ = 43662528. Its totient is φ = 7793280.

The previous prime is 20130797. The next prime is 20130829. The reversal of 20130820 is 2803102.

It is a happy number.

It is a junction number, because it is equal to n+sod(n) for n = 20130794 and 20130803.

It is not an unprimeable number, because it can be changed into a prime (20130829) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 111130 + ... + 111310.

It is an arithmetic number, because the mean of its divisors is an integer number (909636).

Almost surely, 2^20130820 is an apocalyptic number.

20130820 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20130820 is an abundant number, since it is smaller than the sum of its proper divisors (23531708).

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

20130820 is a wasteful number, since it uses less digits than its factorization.

20130820 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 340 (or 338 counting only the distinct ones).

The product of its (nonzero) digits is 96, while the sum is 16.

The square root of 20130820 is about 4486.7382361800. The cubic root of 20130820 is about 272.0323094549.

Adding to 20130820 its reverse (2803102), we get a palindrome (22933922).

The spelling of 20130820 in words is "twenty million, one hundred thirty thousand, eight hundred twenty".