21102120210020 has 24 divisors (see below), whose sum is σ = 44975862181824. Its totient is φ = 8314865276256.

The previous prime is 21102120210019. The next prime is 21102120210071. The reversal of 21102120210020 is 2001202120112.

It is a junction number, because it is equal to n+sod(n) for n = 21102120209977 and 21102120210004.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 7873924112 + ... + 7873926791.

It is an arithmetic number, because the mean of its divisors is an integer number (1873994257576).

Almost surely, 2^{21102120210020} is an apocalyptic number.

21102120210020 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21102120210020 is an abundant number, since it is smaller than the sum of its proper divisors (23873741971804).

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

21102120210020 is a wasteful number, since it uses less digits than its factorization.

21102120210020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15747850979 (or 15747850977 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 14.

Adding to 21102120210020 its reverse (2001202120112), we get a palindrome (23103322330132).

The spelling of 21102120210020 in words is "twenty-one trillion, one hundred two billion, one hundred twenty million, two hundred ten thousand, twenty".