20816338560 has 128 divisors (see below), whose sum is σ = 66392697600. Its totient is φ = 5547626496.

The previous prime is 20816338553. The next prime is 20816338561. The reversal of 20816338560 is 6583361802.

It is a tau number, because it is divible by the number of its divisors (128).

It is not an unprimeable number, because it can be changed into a prime (20816338561) 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, 5583417 + ... + 5587143.

It is an arithmetic number, because the mean of its divisors is an integer number (518692950).

Almost surely, 2^20816338560 is an apocalyptic number.

20816338560 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 20816338560, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (33196348800).

20816338560 is an abundant number, since it is smaller than the sum of its proper divisors (45576359040).

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

20816338560 is a wasteful number, since it uses less digits than its factorization.

20816338560 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6658 (or 6646 counting only the distinct ones).

The product of its (nonzero) digits is 207360, while the sum is 42.

The spelling of 20816338560 in words is "twenty billion, eight hundred sixteen million, three hundred thirty-eight thousand, five hundred sixty".