21202101211 has 4 divisors (see below), whose sum is σ = 21420679672. Its totient is φ = 20983522752.

The previous prime is 21202101199. The next prime is 21202101227. The reversal of 21202101211 is 11210120212.

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 21202101211 - 2¹⁹ = 21201576923 is a prime.

It is a super-2 number, since 2×21202101211² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21202101191 and 21202101200.

It is not an unprimeable number, because it can be changed into a prime (21202101251) 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, 109289085 + ... + 109289278.

It is an arithmetic number, because the mean of its divisors is an integer number (5355169918).

Almost surely, 2^21202101211 is an apocalyptic number.

21202101211 is a deficient number, since it is larger than the sum of its proper divisors (218578461).

21202101211 is an equidigital number, since it uses as much as digits as its factorization.

21202101211 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 218578460.

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

Adding to 21202101211 its reverse (11210120212), we get a palindrome (32412221423).

The spelling of 21202101211 in words is "twenty-one billion, two hundred two million, one hundred one thousand, two hundred eleven".