21220212111 has 24 divisors (see below), whose sum is σ = 34127017344. Its totient is φ = 11487629520.

The previous prime is 21220212067. The next prime is 21220212157. The reversal of 21220212111 is 11121202212.

It is not a de Polignac number, because 21220212111 - 2¹³ = 21220203919 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21220212011) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1391985 + ... + 1407146.

It is an arithmetic number, because the mean of its divisors is an integer number (1421959056).

Almost surely, 2^21220212111 is an apocalyptic number.

21220212111 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

21220212111 is a deficient number, since it is larger than the sum of its proper divisors (12906805233).

21220212111 is a wasteful number, since it uses less digits than its factorization.

21220212111 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2799179 (or 2799160 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 15.

Adding to 21220212111 its reverse (11121202212), we get a palindrome (32341414323).

The spelling of 21220212111 in words is "twenty-one billion, two hundred twenty million, two hundred twelve thousand, one hundred eleven".