21210220210111 has 4 divisors (see below), whose sum is σ = 21210234810912. Its totient is φ = 21210205609312.

The previous prime is 21210220210073. The next prime is 21210220210163. The reversal of 21210220210111 is 11101202201212.

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-21210220210111 is a prime.

It is a super-2 number, since 2×21210220210111² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21210220217111) 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, 4846426 + ... + 8118391.

It is an arithmetic number, because the mean of its divisors is an integer number (5302558702728).

Almost surely, 2^{21210220210111} is an apocalyptic number.

21210220210111 is a deficient number, since it is larger than the sum of its proper divisors (14600801).

21210220210111 is a wasteful number, since it uses less digits than its factorization.

21210220210111 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14600800.

The product of its (nonzero) digits is 32, while the sum is 16.

Adding to 21210220210111 its reverse (11101202201212), we get a palindrome (32311422411323).

The spelling of 21210220210111 in words is "twenty-one trillion, two hundred ten billion, two hundred twenty million, two hundred ten thousand, one hundred eleven".