20855935890 has 80 divisors (see below), whose sum is σ = 56128027032. Its totient is φ = 5556750336.

The previous prime is 20855935889. The next prime is 20855935897. The reversal of 20855935890 is 9853955802.

20855935890 is a `hidden beast` number, since 2 + 0 + 8 + 5 + 59 + 3 + 589 + 0 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 8931951081 + 11923984809 = 94509^2 + 109197^2 .

It is a Harshad number since it is a multiple of its sum of digits (54).

It is not an unprimeable number, because it can be changed into a prime (20855935897) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 975192 + ... + 996348.

Almost surely, 2^20855935890 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20855935890, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28064013516).

20855935890 is an abundant number, since it is smaller than the sum of its proper divisors (35272091142).

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

20855935890 is a wasteful number, since it uses less digits than its factorization.

20855935890 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22393 (or 22384 counting only the distinct ones).

The product of its (nonzero) digits is 3888000, while the sum is 54.

The spelling of 20855935890 in words is "twenty billion, eight hundred fifty-five million, nine hundred thirty-five thousand, eight hundred ninety".