21121012110020 has 96 divisors (see below), whose sum is σ = 48061234666368. Its totient is φ = 7765573036032.

The previous prime is 21121012109999. The next prime is 21121012110031. The reversal of 21121012110020 is 2001121012112.

It is a super-2 number, since 2×21121012110020² (a number of 27 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21121012109977 and 21121012110004.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 125604119 + ... + 125772161.

It is an arithmetic number, because the mean of its divisors is an integer number (500637861108).

Almost surely, 2^{21121012110020} is an apocalyptic number.

21121012110020 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 21121012110020, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24030617333184).

21121012110020 is an abundant number, since it is smaller than the sum of its proper divisors (26940222556348).

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

21121012110020 is a wasteful number, since it uses less digits than its factorization.

21121012110020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 176709 (or 176707 counting only the distinct ones).

The product of its (nonzero) digits is 16, while the sum is 14.

Adding to 21121012110020 its reverse (2001121012112), we get a palindrome (23122133122132).

The spelling of 21121012110020 in words is "twenty-one trillion, one hundred twenty-one billion, twelve million, one hundred ten thousand, twenty".