20818434208 has 192 divisors, whose sum is σ = 50676192000. Its totient is φ = 8288870400.

The previous prime is 20818434179. The next prime is 20818434229. The reversal of 20818434208 is 80243481802.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 6940293 + ... + 6943291.

It is an arithmetic number, because the mean of its divisors is an integer number (263938500).

Almost surely, 2^20818434208 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20818434208, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25338096000).

20818434208 is an abundant number, since it is smaller than the sum of its proper divisors (29857757792).

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

20818434208 is a wasteful number, since it uses less digits than its factorization.

20818434208 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3111 (or 3103 counting only the distinct ones).

The product of its (nonzero) digits is 98304, while the sum is 40.

The spelling of 20818434208 in words is "twenty billion, eight hundred eighteen million, four hundred thirty-four thousand, two hundred eight".