21021020211 has 8 divisors (see below), whose sum is σ = 28029911184. Its totient is φ = 14013071360.

The previous prime is 21021020161. The next prime is 21021020239. The reversal of 21021020211 is 11202012012.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21021020211 - 2¹⁴ = 21021003827 is a prime.

It is a super-2 number, since 2×21021020211² (a number of 21 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21021027211) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 181710 + ... + 273971.

It is an arithmetic number, because the mean of its divisors is an integer number (3503738898).

Almost surely, 2^21021020211 is an apocalyptic number.

21021020211 is a deficient number, since it is larger than the sum of its proper divisors (7008890973).

21021020211 is a wasteful number, since it uses less digits than its factorization.

21021020211 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 471061.

The product of its (nonzero) digits is 16, while the sum is 12.

Adding to 21021020211 its reverse (11202012012), we get a palindrome (32223032223).

The spelling of 21021020211 in words is "twenty-one billion, twenty-one million, twenty thousand, two hundred eleven".