21210212011111 has 16 divisors (see below), whose sum is σ = 21277707671584. Its totient is φ = 21142844964864.

The previous prime is 21210212011103. The next prime is 21210212011123. The reversal of 21210212011111 is 11111021201212.

It is a cyclic number.

It is not a de Polignac number, because 21210212011111 - 2³ = 21210212011103 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 (21210212011141) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1761200656 + ... + 1761212698.

It is an arithmetic number, because the mean of its divisors is an integer number (1329856729474).

Almost surely, 2^{21210212011111} is an apocalyptic number.

21210212011111 is a deficient number, since it is larger than the sum of its proper divisors (67495660473).

21210212011111 is a wasteful number, since it uses less digits than its factorization.

21210212011111 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16930.

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

Adding to 21210212011111 its reverse (11111021201212), we get a palindrome (32321233212323).

The spelling of 21210212011111 in words is "twenty-one trillion, two hundred ten billion, two hundred twelve million, eleven thousand, one hundred eleven".