21002112011211 has 4 divisors (see below), whose sum is σ = 28002816014952. Its totient is φ = 14001408007472.

The previous prime is 21002112011173. The next prime is 21002112011219. The reversal of 21002112011211 is 11211021120012.

It is a happy number.

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 21002112011211 - 2²¹ = 21002109914059 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21002112011219) 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, 3500352001866 + ... + 3500352001871.

It is an arithmetic number, because the mean of its divisors is an integer number (7000704003738).

Almost surely, 2^{21002112011211} is an apocalyptic number.

21002112011211 is a deficient number, since it is larger than the sum of its proper divisors (7000704003741).

21002112011211 is an equidigital number, since it uses as much as digits as its factorization.

21002112011211 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7000704003740.

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

Adding to 21002112011211 its reverse (11211021120012), we get a palindrome (32213133131223).

The spelling of 21002112011211 in words is "twenty-one trillion, two billion, one hundred twelve million, eleven thousand, two hundred eleven".