20885810556 has 96 divisors (see below), whose sum is σ = 55447741440. Its totient is φ = 6072724224.

The previous prime is 20885810531. The next prime is 20885810573. The reversal of 20885810556 is 65501858802.

It is a super-2 number, since 2×20885810556² (a number of 21 digits) contains 22 as substring.

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, 163515 + ... + 261741.

It is an arithmetic number, because the mean of its divisors is an integer number (577580640).

Almost surely, 2^20885810556 is an apocalyptic number.

20885810556 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 20885810556, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27723870720).

20885810556 is an abundant number, since it is smaller than the sum of its proper divisors (34561930884).

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

20885810556 is a wasteful number, since it uses less digits than its factorization.

20885810556 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 98323 (or 98321 counting only the distinct ones).

The product of its (nonzero) digits is 768000, while the sum is 48.

The spelling of 20885810556 in words is "twenty billion, eight hundred eighty-five million, eight hundred ten thousand, five hundred fifty-six".