21212120100111 has 4 divisors (see below), whose sum is σ = 28282826800152. Its totient is φ = 14141413400072.

The previous prime is 21212120100109. The next prime is 21212120100113. The reversal of 21212120100111 is 11100102121212.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is an interprime number because it is at equal distance from previous prime (21212120100109) and next prime (21212120100113).

It is a cyclic number.

It is not a de Polignac number, because 21212120100111 - 2¹ = 21212120100109 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21212120100113) 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, 3535353350016 + ... + 3535353350021.

It is an arithmetic number, because the mean of its divisors is an integer number (7070706700038).

Almost surely, 2^{21212120100111} is an apocalyptic number.

21212120100111 is a deficient number, since it is larger than the sum of its proper divisors (7070706700041).

21212120100111 is an equidigital number, since it uses as much as digits as its factorization.

21212120100111 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7070706700040.

The product of its (nonzero) digits is 16, while the sum is 15.

Adding to 21212120100111 its reverse (11100102121212), we get a palindrome (32312222221323).

The spelling of 21212120100111 in words is "twenty-one trillion, two hundred twelve billion, one hundred twenty million, one hundred thousand, one hundred eleven".