21111110100020 has 24 divisors (see below), whose sum is σ = 44517286951368. Its totient is φ = 8409404851200.

The previous prime is 21111110100013. The next prime is 21111110100029. The reversal of 21111110100020 is 2000101111112.

It can be written as a sum of positive squares in 4 ways, for example, as 5917922251684 + 15193187848336 = 2432678^2 + 3897844^2 .

It is a super-3 number, since 3×21111110100020³ (a number of 41 digits) contains 333 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21111110099974 and 21111110100010.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21111110100029) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2189944361 + ... + 2189954000.

It is an arithmetic number, because the mean of its divisors is an integer number (1854886956307).

Almost surely, 2^{21111110100020} is an apocalyptic number.

21111110100020 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21111110100020 is an abundant number, since it is smaller than the sum of its proper divisors (23406176851348).

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

21111110100020 is a wasteful number, since it uses less digits than its factorization.

21111110100020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4379898611 (or 4379898609 counting only the distinct ones).

The product of its (nonzero) digits is 4, while the sum is 11.

Adding to 21111110100020 its reverse (2000101111112), we get a palindrome (23111211211132).

The spelling of 21111110100020 in words is "twenty-one trillion, one hundred eleven billion, one hundred ten million, one hundred thousand, twenty".