21110100202021 has 4 divisors (see below), whose sum is σ = 21170587595500. Its totient is φ = 21049612808544.

The previous prime is 21110100202019. The next prime is 21110100202027. The reversal of 21110100202021 is 12020200101112.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 11803244292225 + 9306855909796 = 3435585^2 + 3050714^2 .

It is a cyclic number.

It is not a de Polignac number, because 21110100202021 - 2¹ = 21110100202019 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21110100201992 and 21110100202010.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21110100202027) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 30243696216 + ... + 30243696913.

It is an arithmetic number, because the mean of its divisors is an integer number (5292646898875).

Almost surely, 2^{21110100202021} is an apocalyptic number.

It is an amenable number.

21110100202021 is a deficient number, since it is larger than the sum of its proper divisors (60487393479).

21110100202021 is an equidigital number, since it uses as much as digits as its factorization.

21110100202021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 60487393478.

The product of its (nonzero) digits is 16, while the sum is 13.

Adding to 21110100202021 its reverse (12020200101112), we get a palindrome (33130300303133).

The spelling of 21110100202021 in words is "twenty-one trillion, one hundred ten billion, one hundred million, two hundred two thousand, twenty-one".