20983821768 has 448 divisors, whose sum is σ = 76461033600. Its totient is φ = 5240401920.

The previous prime is 20983821743. The next prime is 20983821773. The reversal of 20983821768 is 86712838902.

It is a happy number.

20983821768 is a `hidden beast` number, since 2 + 0 + 98 + 382 + 176 + 8 = 666.

It is a Harshad number since it is a multiple of its sum of digits (54).

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 111 ways as a sum of consecutive naturals, for example, 10082488 + ... + 10084568.

It is an arithmetic number, because the mean of its divisors is an integer number (170671950).

Almost surely, 2^20983821768 is an apocalyptic number.

20983821768 is a gapful number since it is divisible by the number (28) 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 20983821768, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (38230516800).

20983821768 is an abundant number, since it is smaller than the sum of its proper divisors (55477211832).

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

20983821768 is a wasteful number, since it uses less digits than its factorization.

20983821768 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2144 (or 2125 counting only the distinct ones).

The product of its (nonzero) digits is 2322432, while the sum is 54.

The spelling of 20983821768 in words is "twenty billion, nine hundred eighty-three million, eight hundred twenty-one thousand, seven hundred sixty-eight".