21212011221111 has 24 divisors (see below), whose sum is σ = 30768204491024. Its totient is φ = 14081977578240.

The previous prime is 21212011221077. The next prime is 21212011221119. The reversal of 21212011221111 is 11112211021212.

It is a happy number.

21212011221111 is a `hidden beast` number, since 212 + 120 + 1 + 1 + 221 + 111 = 666.

It is not a de Polignac number, because 21212011221111 - 2¹⁸ = 21212010958967 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21212011221119) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 46443120 + ... + 46897626.

Almost surely, 2^{21212011221111} is an apocalyptic number.

21212011221111 is a deficient number, since it is larger than the sum of its proper divisors (9556193269913).

21212011221111 is a wasteful number, since it uses less digits than its factorization.

21212011221111 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 476271 (or 476268 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 18.

Adding to 21212011221111 its reverse (11112211021212), we get a palindrome (32324222242323).

The spelling of 21212011221111 in words is "twenty-one trillion, two hundred twelve billion, eleven million, two hundred twenty-one thousand, one hundred eleven".