20580820 has 36 divisors (see below), whose sum is σ = 46807740. Its totient is φ = 7597824.

The previous prime is 20580809. The next prime is 20580821. The reversal of 20580820 is 2808502.

It can be written as a sum of positive squares in 6 ways, for example, as 6697744 + 13883076 = 2588^2 + 3726^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20580821) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 336 + ... + 6424.

It is an arithmetic number, because the mean of its divisors is an integer number (1300215).

Almost surely, 2^20580820 is an apocalyptic number.

20580820 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20580820, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (23403870).

20580820 is an abundant number, since it is smaller than the sum of its proper divisors (26226920).

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

20580820 is a wasteful number, since it uses less digits than its factorization.

20580820 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6124 (or 6109 counting only the distinct ones).

The product of its (nonzero) digits is 1280, while the sum is 25.

The square root of 20580820 is about 4536.6088656617. The cubic root of 20580820 is about 274.0443745063.

The spelling of 20580820 in words is "twenty million, five hundred eighty thousand, eight hundred twenty".