21120220021211 has 4 divisors (see below), whose sum is σ = 21120493396800. Its totient is φ = 21119946645624.

The previous prime is 21120220021129. The next prime is 21120220021297. The reversal of 21120220021211 is 11212002202112.

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 21120220021211 - 2³⁴ = 21103040152027 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21120220021211.

It is not an unprimeable number, because it can be changed into a prime (21120220027211) 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, 136571876 + ... + 136726433.

It is an arithmetic number, because the mean of its divisors is an integer number (5280123349200).

Almost surely, 2^{21120220021211} is an apocalyptic number.

21120220021211 is a deficient number, since it is larger than the sum of its proper divisors (273375589).

21120220021211 is an equidigital number, since it uses as much as digits as its factorization.

21120220021211 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 273375588.

The product of its (nonzero) digits is 64, while the sum is 17.

Adding to 21120220021211 its reverse (11212002202112), we get a palindrome (32332222223323).

The spelling of 21120220021211 in words is "twenty-one trillion, one hundred twenty billion, two hundred twenty million, twenty-one thousand, two hundred eleven".