21120011121211 has 4 divisors (see below), whose sum is σ = 21848287366800. Its totient is φ = 20391734875624.

The previous prime is 21120011121173. The next prime is 21120011121217. The reversal of 21120011121211 is 11212111002112.

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 21120011121211 - 2⁹ = 21120011120699 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21120011121217) 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, 364138122751 + ... + 364138122808.

It is an arithmetic number, because the mean of its divisors is an integer number (5462071841700).

Almost surely, 2^{21120011121211} is an apocalyptic number.

21120011121211 is a deficient number, since it is larger than the sum of its proper divisors (728276245589).

21120011121211 is an equidigital number, since it uses as much as digits as its factorization.

21120011121211 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 728276245588.

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

Adding to 21120011121211 its reverse (11212111002112), we get a palindrome (32332122123323).

The spelling of 21120011121211 in words is "twenty-one trillion, one hundred twenty billion, eleven million, one hundred twenty-one thousand, two hundred eleven".