20812221792 has 144 divisors (see below), whose sum is σ = 60393295872. Its totient is φ = 6796880640.

The previous prime is 20812221791. The next prime is 20812221811. The reversal of 20812221792 is 29712221802.

It is a tau number, because it is divible by the number of its divisors (144).

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20812221791) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 3682713 + ... + 3688359.

It is an arithmetic number, because the mean of its divisors is an integer number (419397888).

Almost surely, 2^20812221792 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 20812221792, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (30196647936).

20812221792 is an abundant number, since it is smaller than the sum of its proper divisors (39581074080).

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

20812221792 is a wasteful number, since it uses less digits than its factorization.

20812221792 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5921 (or 5910 counting only the distinct ones).

The product of its (nonzero) digits is 16128, while the sum is 36.

The spelling of 20812221792 in words is "twenty billion, eight hundred twelve million, two hundred twenty-one thousand, seven hundred ninety-two".