20643840000 has 600 divisors, whose sum is σ = 85169455800. Its totient is φ = 4718592000.

The previous prime is 20643839981. The next prime is 20643840023. The reversal of 20643840000 is 4834602.

It is a tau number, because it is divible by the number of its divisors (600).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 29 ways as a sum of consecutive naturals, for example, 2949119997 + ... + 2949120003.

It is an arithmetic number, because the mean of its divisors is an integer number (141949093).

Almost surely, 2^20643840000 is an apocalyptic number.

20643840000 is a gapful number since it is divisible by the number (20) 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 20643840000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (42584727900).

20643840000 is an abundant number, since it is smaller than the sum of its proper divisors (64525615800).

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

20643840000 is an frugal number, since it uses more digits than its factorization.

20643840000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 71 (or 17 counting only the distinct ones).

The product of its (nonzero) digits is 4608, while the sum is 27.

The spelling of 20643840000 in words is "twenty billion, six hundred forty-three million, eight hundred forty thousand".