21111121200011 has 4 divisors (see below), whose sum is σ = 21602077507032. Its totient is φ = 20620164892992.

The previous prime is 21111121199953. The next prime is 21111121200023. The reversal of 21111121200011 is 11000212111112.

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 21111121200011 - 2²⁶ = 21111054091147 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21111121200031) 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, 245478153446 + ... + 245478153531.

It is an arithmetic number, because the mean of its divisors is an integer number (5400519376758).

Almost surely, 2^{21111121200011} is an apocalyptic number.

21111121200011 is a deficient number, since it is larger than the sum of its proper divisors (490956307021).

21111121200011 is an equidigital number, since it uses as much as digits as its factorization.

21111121200011 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 490956307020.

The product of its (nonzero) digits is 8, while the sum is 14.

Adding to 21111121200011 its reverse (11000212111112), we get a palindrome (32111333311123).

The spelling of 21111121200011 in words is "twenty-one trillion, one hundred eleven billion, one hundred twenty-one million, two hundred thousand, eleven".