21001120200020 has 12 divisors (see below), whose sum is σ = 44102352420084. Its totient is φ = 8400448080000.

The previous prime is 21001120199933. The next prime is 21001120200089. The reversal of 21001120200020 is 2000202110012.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 15338157628816 + 5662962571204 = 3916396^2 + 2379698^2 .

It is a junction number, because it is equal to n+sod(n) for n = 21001120199974 and 21001120200010.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 525028004981 + ... + 525028005020.

It is an arithmetic number, because the mean of its divisors is an integer number (3675196035007).

Almost surely, 2^{21001120200020} is an apocalyptic number.

21001120200020 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21001120200020 is an abundant number, since it is smaller than the sum of its proper divisors (23101232220064).

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

21001120200020 is a wasteful number, since it uses less digits than its factorization.

21001120200020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1050056010010 (or 1050056010008 counting only the distinct ones).

The product of its (nonzero) digits is 16, while the sum is 11.

Adding to 21001120200020 its reverse (2000202110012), we get a palindrome (23001322310032).

The spelling of 21001120200020 in words is "twenty-one trillion, one billion, one hundred twenty million, two hundred thousand, twenty".