20011221011100 has 288 divisors, whose sum is σ = 64504878923520. Its totient is φ = 4749198080000.

The previous prime is 20011221011081. The next prime is 20011221011129. The reversal of 20011221011100 is 111012211002.

It is a Harshad number since it is a multiple of its sum of digits (12).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 29326399 + ... + 30001001.

It is an arithmetic number, because the mean of its divisors is an integer number (223975274040).

Almost surely, 2^{20011221011100} is an apocalyptic number.

20011221011100 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 20011221011100, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (32252439461760).

20011221011100 is an abundant number, since it is smaller than the sum of its proper divisors (44493657912420).

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

20011221011100 is a wasteful number, since it uses less digits than its factorization.

20011221011100 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 674821 (or 674814 counting only the distinct ones).

The product of its (nonzero) digits is 8, while the sum is 12.

Adding to 20011221011100 its reverse (111012211002), we get a palindrome (20122233222102).

It can be divided in two parts, 200112 and 21011100, that added together give a palindrome (21211212).

The spelling of 20011221011100 in words is "twenty trillion, eleven billion, two hundred twenty-one million, eleven thousand, one hundred".