21230111100 has 144 divisors (see below), whose sum is σ = 67065707520. Its totient is φ = 5142412800.

The previous prime is 21230111099. The next prime is 21230111101. The reversal of 21230111100 is 111103212.

It is an interprime number because it is at equal distance from previous prime (21230111099) and next prime (21230111101).

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 (21230111101) by changing a digit.

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 47 ways as a sum of consecutive naturals, for example, 6014136 + ... + 6017664.

It is an arithmetic number, because the mean of its divisors is an integer number (465734080).

Almost surely, 2^21230111100 is an apocalyptic number.

21230111100 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 21230111100, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (33532853760).

21230111100 is an abundant number, since it is smaller than the sum of its proper divisors (45835596420).

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

21230111100 is a wasteful number, since it uses less digits than its factorization.

21230111100 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5380 (or 5373 counting only the distinct ones).

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

Adding to 21230111100 its reverse (111103212), we get a palindrome (21341214312).

The spelling of 21230111100 in words is "twenty-one billion, two hundred thirty million, one hundred eleven thousand, one hundred".