20718909639792 has 960 divisors, whose sum is σ = 79323604214400. Its totient is φ = 5114273955840.

The previous prime is 20718909639761. The next prime is 20718909639881. The reversal of 20718909639792 is 29793690981702.

20718909639792 is a `hidden beast` number, since 2 + 0 + 71 + 89 + 0 + 9 + 6 + 397 + 92 = 666.

It is a Harshad number since it is a multiple of its sum of digits (72).

It is a self number, because there is not a number n which added to its sum of digits gives 20718909639792.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (29) of ones.

It is a polite number, since it can be written in 191 ways as a sum of consecutive naturals, for example, 846728934 + ... + 846753402.

It is an arithmetic number, because the mean of its divisors is an integer number (82628754390).

Almost surely, 2^{20718909639792} 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 20718909639792, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (39661802107200).

20718909639792 is an abundant number, since it is smaller than the sum of its proper divisors (58604694574608).

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

20718909639792 is a wasteful number, since it uses less digits than its factorization.

20718909639792 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 24711 (or 24692 counting only the distinct ones).

The product of its (nonzero) digits is 185177664, while the sum is 72.

The spelling of 20718909639792 in words is "twenty trillion, seven hundred eighteen billion, nine hundred nine million, six hundred thirty-nine thousand, seven hundred ninety-two".