21020112002021 has 12 divisors (see below), whose sum is σ = 23104956720300. Its totient is φ = 19109022757440.

The previous prime is 21020112002017. The next prime is 21020112002039. The reversal of 21020112002021 is 12020021102012.

It can be written as a sum of positive squares in 2 ways, for example, as 124105425796 + 20896006576225 = 352286^2 + 4571215^2 .

It is not a de Polignac number, because 21020112002021 - 2² = 21020112002017 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21020112001987 and 21020112002005.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21020112002011) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 14058785 + ... + 15481913.

It is an arithmetic number, because the mean of its divisors is an integer number (1925413060025).

Almost surely, 2^{21020112002021} is an apocalyptic number.

It is an amenable number.

21020112002021 is a deficient number, since it is larger than the sum of its proper divisors (2084844718279).

21020112002021 is a wasteful number, since it uses less digits than its factorization.

21020112002021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1545220 (or 1545209 counting only the distinct ones).

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

Adding to 21020112002021 its reverse (12020021102012), we get a palindrome (33040133104033).

Subtracting from 21020112002021 its reverse (12020021102012), we obtain a palindrome (9000090900009).

The spelling of 21020112002021 in words is "twenty-one trillion, twenty billion, one hundred twelve million, two thousand, twenty-one".