20818304820 has 288 divisors, whose sum is σ = 68031774720. Its totient is φ = 5141283840.

The previous prime is 20818304809. The next prime is 20818304861. The reversal of 20818304820 is 2840381802.

It is a happy number.

20818304820 is a `hidden beast` number, since 20 + 81 + 83 + 0 + 482 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 20550634 + ... + 20551646.

It is an arithmetic number, because the mean of its divisors is an integer number (236221440).

Almost surely, 2^20818304820 is an apocalyptic number.

20818304820 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 20818304820, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (34015887360).

20818304820 is an abundant number, since it is smaller than the sum of its proper divisors (47213469900).

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

20818304820 is a wasteful number, since it uses less digits than its factorization.

20818304820 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1215 (or 1210 counting only the distinct ones).

The product of its (nonzero) digits is 24576, while the sum is 36.

The spelling of 20818304820 in words is "twenty billion, eight hundred eighteen million, three hundred four thousand, eight hundred twenty".