21020112100020 has 192 divisors, whose sum is σ = 65582804238336. Its totient is φ = 4986617502720.

The previous prime is 21020112100007. The next prime is 21020112100021. The reversal of 21020112100020 is 2000121102012.

It is a super-2 number, since 2×21020112100020² (a number of 27 digits) contains 22 as substring.

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

It is a junction number, because it is equal to n+sod(n) for n = 21020112099969 and 21020112100005.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21020112100021) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 223079757 + ... + 223173963.

It is an arithmetic number, because the mean of its divisors is an integer number (341577105408).

Almost surely, 2^{21020112100020} is an apocalyptic number.

21020112100020 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 21020112100020, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (32791402119168).

21020112100020 is an abundant number, since it is smaller than the sum of its proper divisors (44562692138316).

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

21020112100020 is a wasteful number, since it uses less digits than its factorization.

21020112100020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 101470 (or 101468 counting only the distinct ones).

The product of its (nonzero) digits is 16, while the sum is 12.

Adding to 21020112100020 its reverse (2000121102012), we get a palindrome (23020233202032).

The spelling of 21020112100020 in words is "twenty-one trillion, twenty billion, one hundred twelve million, one hundred thousand, twenty".