21220210111 has 4 divisors (see below), whose sum is σ = 21220655400. Its totient is φ = 21219764824.

The previous prime is 21220210087. The next prime is 21220210133. The reversal of 21220210111 is 11101202212.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21220210111 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21220210091 and 21220210100.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21220210171) 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, 141241 + ... + 249778.

It is an arithmetic number, because the mean of its divisors is an integer number (5305163850).

Almost surely, 2^21220210111 is an apocalyptic number.

21220210111 is a deficient number, since it is larger than the sum of its proper divisors (445289).

21220210111 is an equidigital number, since it uses as much as digits as its factorization.

21220210111 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 445288.

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

Adding to 21220210111 its reverse (11101202212), we get a palindrome (32321412323).

The spelling of 21220210111 in words is "twenty-one billion, two hundred twenty million, two hundred ten thousand, one hundred eleven".