21021021020211 has 4 divisors (see below), whose sum is σ = 28028028026952. Its totient is φ = 14014014013472.

The previous prime is 21021021020117. The next prime is 21021021020227. The reversal of 21021021020211 is 11202012012012.

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

It is a cyclic number.

It is not a de Polignac number, because 21021021020211 - 2²¹ = 21021018923059 is a prime.

It is a super-2 number, since 2×21021021020211² (a number of 27 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21021021027211) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3503503503366 + ... + 3503503503371.

It is an arithmetic number, because the mean of its divisors is an integer number (7007007006738).

Almost surely, 2^{21021021020211} is an apocalyptic number.

21021021020211 is a deficient number, since it is larger than the sum of its proper divisors (7007007006741).

21021021020211 is an equidigital number, since it uses as much as digits as its factorization.

21021021020211 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7007007006740.

The product of its (nonzero) digits is 32, while the sum is 15.

Adding to 21021021020211 its reverse (11202012012012), we get a palindrome (32223033032223).

The spelling of 21021021020211 in words is "twenty-one trillion, twenty-one billion, twenty-one million, twenty thousand, two hundred eleven".