20011021211 has 4 divisors (see below), whose sum is σ = 20014981800. Its totient is φ = 20007060624.

The previous prime is 20011021201. The next prime is 20011021231. The reversal of 20011021211 is 11212011002.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 11212011002 = 2 ⋅5606005501.

It is a cyclic number.

It is not a de Polignac number, because 20011021211 - 2²⁶ = 19943912347 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 20011021192 and 20011021201.

It is not an unprimeable number, because it can be changed into a prime (20011021201) 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, 1972706 + ... + 1982823.

It is an arithmetic number, because the mean of its divisors is an integer number (5003745450).

Almost surely, 2^20011021211 is an apocalyptic number.

20011021211 is a deficient number, since it is larger than the sum of its proper divisors (3960589).

20011021211 is an equidigital number, since it uses as much as digits as its factorization.

20011021211 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3960588.

The product of its (nonzero) digits is 8, while the sum is 11.

Adding to 20011021211 its reverse (11212011002), we get a palindrome (31223032213).

The spelling of 20011021211 in words is "twenty billion, eleven million, twenty-one thousand, two hundred eleven".