20784187872 has 240 divisors, whose sum is σ = 70004021472. Its totient is φ = 5925934080.

The previous prime is 20784187867. The next prime is 20784187909. The reversal of 20784187872 is 27878148702.

20784187872 is a `hidden beast` number, since 20 + 78 + 418 + 78 + 72 = 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 (17) of ones.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 11992318 + ... + 11994050.

Almost surely, 2^20784187872 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 20784187872, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (35002010736).

20784187872 is an abundant number, since it is smaller than the sum of its proper divisors (49219833600).

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

20784187872 is a wasteful number, since it uses less digits than its factorization.

20784187872 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2423 (or 2406 counting only the distinct ones).

The product of its (nonzero) digits is 2809856, while the sum is 54.

The spelling of 20784187872 in words is "twenty billion, seven hundred eighty-four million, one hundred eighty-seven thousand, eight hundred seventy-two".