21020202212111 has 4 divisors (see below), whose sum is σ = 21025833129912. Its totient is φ = 21014571294312.

The previous prime is 21020202212083. The next prime is 21020202212117. The reversal of 21020202212111 is 11121220202012.

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-21020202212111 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21020202212111.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21020202212117) 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, 2815453301 + ... + 2815460766.

It is an arithmetic number, because the mean of its divisors is an integer number (5256458282478).

Almost surely, 2^{21020202212111} is an apocalyptic number.

21020202212111 is a deficient number, since it is larger than the sum of its proper divisors (5630917801).

21020202212111 is an equidigital number, since it uses as much as digits as its factorization.

21020202212111 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5630917800.

The product of its (nonzero) digits is 64, while the sum is 17.

Adding to 21020202212111 its reverse (11121220202012), we get a palindrome (32141422414123).

The spelling of 21020202212111 in words is "twenty-one trillion, twenty billion, two hundred two million, two hundred twelve thousand, one hundred eleven".