20881001856 has 192 divisors, whose sum is σ = 65522139840. Its totient is φ = 5840640000.

The previous prime is 20881001849. The next prime is 20881001873. The reversal of 20881001856 is 65810018802.

It is a tau number, because it is divible by the number of its divisors (192).

It is a Harshad number since it is a multiple of its sum of digits (39).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 699231 + ... + 728481.

It is an arithmetic number, because the mean of its divisors is an integer number (341261145).

Almost surely, 2^20881001856 is an apocalyptic number.

20881001856 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 20881001856, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (32761069920).

20881001856 is an abundant number, since it is smaller than the sum of its proper divisors (44641137984).

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

20881001856 is a wasteful number, since it uses less digits than its factorization.

20881001856 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 29305 (or 29280 counting only the distinct ones).

The product of its (nonzero) digits is 30720, while the sum is 39.

The spelling of 20881001856 in words is "twenty billion, eight hundred eighty-one million, one thousand, eight hundred fifty-six".