20101221110100 has 144 divisors (see below), whose sum is σ = 62645903391680. Its totient is φ = 4947000652800.

The previous prime is 20101221110071. The next prime is 20101221110101. The reversal of 20101221110100 is 101112210102.

It is a super-3 number, since 3×20101221110100³ (a number of 41 digits) contains 333 as substring.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20101221110101) 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 47 ways as a sum of consecutive naturals, for example, 19028616 + ... + 20057184.

Almost surely, 2^{20101221110100} is an apocalyptic number.

20101221110100 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 20101221110100, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (31322951695840).

20101221110100 is an abundant number, since it is smaller than the sum of its proper divisors (42544682281580).

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

20101221110100 is a wasteful number, since it uses less digits than its factorization.

20101221110100 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1033610 (or 1033603 counting only the distinct ones).

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

Adding to 20101221110100 its reverse (101112210102), we get a palindrome (20202333320202).

The spelling of 20101221110100 in words is "twenty trillion, one hundred one billion, two hundred twenty-one million, one hundred ten thousand, one hundred".