20918753856 has 1008 divisors, whose sum is σ = 84235552128. Its totient is φ = 4877107200.

The previous prime is 20918753797. The next prime is 20918753881. The reversal of 20918753856 is 65835781902.

20918753856 is a `hidden beast` number, since 20 + 9 + 1 + 87 + 538 + 5 + 6 = 666.

It is a tau number, because it is divible by the number of its divisors (1008).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 143 ways as a sum of consecutive naturals, for example, 286558236 + ... + 286558308.

It is an arithmetic number, because the mean of its divisors is an integer number (83567016).

Almost surely, 2^20918753856 is an apocalyptic number.

20918753856 is a gapful number since it is divisible by the number (26) 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 20918753856, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (42117776064).

20918753856 is an abundant number, since it is smaller than the sum of its proper divisors (63316798272).

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

20918753856 is a wasteful number, since it uses less digits than its factorization.

20918753856 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 200 (or 180 counting only the distinct ones).

The product of its (nonzero) digits is 3628800, while the sum is 54.

The spelling of 20918753856 in words is "twenty billion, nine hundred eighteen million, seven hundred fifty-three thousand, eight hundred fifty-six".