21211112111100 has 288 divisors, whose sum is σ = 65926458103296. Its totient is φ = 5251613875200.

The previous prime is 21211112111093. The next prime is 21211112111107. The reversal of 21211112111100 is 111121111212.

It is an interprime number because it is at equal distance from previous prime (21211112111093) and next prime (21211112111107).

It is a super-2 number, since 2×21211112111100² (a number of 27 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (15).

It is a self number, because there is not a number n which added to its sum of digits gives 21211112111100.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21211112111107) by changing a digit.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 107382627 + ... + 107579973.

Almost surely, 2^{21211112111100} is an apocalyptic number.

21211112111100 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 21211112111100, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (32963229051648).

21211112111100 is an abundant number, since it is smaller than the sum of its proper divisors (44715345992196).

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

21211112111100 is a wasteful number, since it uses less digits than its factorization.

21211112111100 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 197845 (or 197838 counting only the distinct ones).

The product of its (nonzero) digits is 8, while the sum is 15.

Adding to 21211112111100 its reverse (111121111212), we get a palindrome (21322233222312).

The spelling of 21211112111100 in words is "twenty-one trillion, two hundred eleven billion, one hundred twelve million, one hundred eleven thousand, one hundred".