20331065556 has 96 divisors (see below), whose sum is σ = 55777075200. Its totient is φ = 6391012320.

The previous prime is 20331065519. The next prime is 20331065569. The reversal of 20331065556 is 65556013302.

20331065556 is a `hidden beast` number, since 2 + 0 + 33 + 10 + 65 + 556 = 666.

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

It is a self number, because there is not a number n which added to its sum of digits gives 20331065556.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 118725 + ... + 234003.

It is an arithmetic number, because the mean of its divisors is an integer number (581011200).

Almost surely, 2^20331065556 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20331065556, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27888537600).

20331065556 is an abundant number, since it is smaller than the sum of its proper divisors (35446009644).

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

20331065556 is a wasteful number, since it uses less digits than its factorization.

20331065556 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 115386 (or 115378 counting only the distinct ones).

The product of its (nonzero) digits is 81000, while the sum is 36.

Adding to 20331065556 its reverse (65556013302), we get a palindrome (85887078858).

The spelling of 20331065556 in words is "twenty billion, three hundred thirty-one million, sixty-five thousand, five hundred fifty-six".