21010111211211 has 4 divisors (see below), whose sum is σ = 28013481614952. Its totient is φ = 14006740807472.

The previous prime is 21010111211203. The next prime is 21010111211251. The reversal of 21010111211211 is 11211211101012.

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

It is a cyclic number.

It is not a de Polignac number, because 21010111211211 - 2³ = 21010111211203 is a prime.

It is a super-3 number, since 3×21010111211211³ (a number of 41 digits) contains 333 as substring.

It is not an unprimeable number, because it can be changed into a prime (21010111211251) 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, 3501685201866 + ... + 3501685201871.

It is an arithmetic number, because the mean of its divisors is an integer number (7003370403738).

Almost surely, 2^{21010111211211} is an apocalyptic number.

21010111211211 is a deficient number, since it is larger than the sum of its proper divisors (7003370403741).

21010111211211 is an equidigital number, since it uses as much as digits as its factorization.

21010111211211 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7003370403740.

The product of its (nonzero) digits is 8, while the sum is 15.

Adding to 21010111211211 its reverse (11211211101012), we get a palindrome (32221322312223).

The spelling of 21010111211211 in words is "twenty-one trillion, ten billion, one hundred eleven million, two hundred eleven thousand, two hundred eleven".