20787974784 has 160 divisors (see below), whose sum is σ = 65121328800. Its totient is φ = 6564561408.

The previous prime is 20787974783. The next prime is 20787974887. The reversal of 20787974784 is 48747978702.

20787974784 is a `hidden beast` number, since 2 + 0 + 78 + 7 + 97 + 478 + 4 = 666.

It is not an unprimeable number, because it can be changed into a prime (20787974783) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 144229 + ... + 249755.

It is an arithmetic number, because the mean of its divisors is an integer number (407008305).

Almost surely, 2^20787974784 is an apocalyptic number.

20787974784 is a gapful number since it is divisible by the number (24) 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 20787974784, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (32560664400).

20787974784 is an abundant number, since it is smaller than the sum of its proper divisors (44333354016).

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

20787974784 is a wasteful number, since it uses less digits than its factorization.

20787974784 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 105572 (or 105551 counting only the distinct ones).

The product of its (nonzero) digits is 44255232, while the sum is 63.

The spelling of 20787974784 in words is "twenty billion, seven hundred eighty-seven million, nine hundred seventy-four thousand, seven hundred eighty-four".