21212100011 has 4 divisors (see below), whose sum is σ = 21287054712. Its totient is φ = 21137145312.

The previous prime is 21212100001. The next prime is 21212100017. The reversal of 21212100011 is 11000121212.

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-21212100011 is a prime.

It is a super-3 number, since 3×21212100011³ (a number of 32 digits) contains 333 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21212099965 and 21212100001.

It is not an unprimeable number, because it can be changed into a prime (21212100017) 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, 37476926 + ... + 37477491.

It is an arithmetic number, because the mean of its divisors is an integer number (5321763678).

Almost surely, 2^21212100011 is an apocalyptic number.

21212100011 is a deficient number, since it is larger than the sum of its proper divisors (74954701).

21212100011 is an equidigital number, since it uses as much as digits as its factorization.

21212100011 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 74954700.

The product of its (nonzero) digits is 8, while the sum is 11.

Adding to 21212100011 its reverse (11000121212), we get a palindrome (32212221223).

The spelling of 21212100011 in words is "twenty-one billion, two hundred twelve million, one hundred thousand, eleven".