21101121020 has 24 divisors (see below), whose sum is σ = 50642690784. Its totient is φ = 7234670016.

The previous prime is 21101120939. The next prime is 21101121029. The reversal of 21101121020 is 2012110112.

It is a junction number, because it is equal to n+sod(n) for n = 21101120992 and 21101121010.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21101121029) 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, 75361007 + ... + 75361286.

It is an arithmetic number, because the mean of its divisors is an integer number (2110112116).

Almost surely, 2^21101121020 is an apocalyptic number.

21101121020 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21101121020 is an abundant number, since it is smaller than the sum of its proper divisors (29541569764).

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

21101121020 is a wasteful number, since it uses less digits than its factorization.

21101121020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 150722309 (or 150722307 counting only the distinct ones).

The product of its (nonzero) digits is 8, while the sum is 11.

Adding to 21101121020 its reverse (2012110112), we get a palindrome (23113231132).

The spelling of 21101121020 in words is "twenty-one billion, one hundred one million, one hundred twenty-one thousand, twenty".