21020221211 has 16 divisors (see below), whose sum is σ = 23071392000. Its totient is φ = 18992719200.

The previous prime is 21020221153. The next prime is 21020221259. The reversal of 21020221211 is 11212202012.

It is a cyclic number.

It is not a de Polignac number, because 21020221211 - 2⁶ = 21020221147 is a prime.

It is a super-3 number, since 3×21020221211³ (a number of 32 digits) contains 333 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21020221511) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1501916 + ... + 1515846.

It is an arithmetic number, because the mean of its divisors is an integer number (1441962000).

Almost surely, 2^21020221211 is an apocalyptic number.

21020221211 is a deficient number, since it is larger than the sum of its proper divisors (2051170789).

21020221211 is a wasteful number, since it uses less digits than its factorization.

21020221211 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14770.

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

Adding to 21020221211 its reverse (11212202012), we get a palindrome (32232423223).

The spelling of 21020221211 in words is "twenty-one billion, twenty million, two hundred twenty-one thousand, two hundred eleven".