21210000110020 has 24 divisors (see below), whose sum is σ = 44547094531800. Its totient is φ = 8482839224832.

The previous prime is 21210000110017. The next prime is 21210000110063. The reversal of 21210000110020 is 2001100001212.

It can be written as a sum of positive squares in 4 ways, for example, as 6101650903104 + 15108349206916 = 2470152^2 + 3886946^2 .

It is a Harshad number since it is a multiple of its sum of digits (10).

It is a junction number, because it is equal to n+sod(n) for n = 21210000109979 and 21210000110006.

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, 72401365 + ... + 72693724.

It is an arithmetic number, because the mean of its divisors is an integer number (1856128938825).

Almost surely, 2^{21210000110020} is an apocalyptic number.

21210000110020 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21210000110020 is an abundant number, since it is smaller than the sum of its proper divisors (23337094421780).

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

21210000110020 is a wasteful number, since it uses less digits than its factorization.

21210000110020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 145102407 (or 145102405 counting only the distinct ones).

The product of its (nonzero) digits is 8, while the sum is 10.

Adding to 21210000110020 its reverse (2001100001212), we get a palindrome (23211100111232).

The spelling of 21210000110020 in words is "twenty-one trillion, two hundred ten billion, one hundred ten thousand, twenty".