20400871680 has 576 divisors, whose sum is σ = 84474432000. Its totient is φ = 4660346880.

The previous prime is 20400871669. The next prime is 20400871681. The reversal of 20400871680 is 8617800402.

It is a tau number, because it is divible by the number of its divisors (576).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a zygodrome in base 8.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20400871681) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 11853220 + ... + 11854940.

It is an arithmetic number, because the mean of its divisors is an integer number (146657000).

Almost surely, 2^20400871680 is an apocalyptic number.

20400871680 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 20400871680, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (42237216000).

20400871680 is an abundant number, since it is smaller than the sum of its proper divisors (64073560320).

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

20400871680 is an equidigital number, since it uses as much as digits as its factorization.

20400871680 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1772 (or 1738 counting only the distinct ones).

The product of its (nonzero) digits is 21504, while the sum is 36.

The spelling of 20400871680 in words is "twenty billion, four hundred million, eight hundred seventy-one thousand, six hundred eighty".