20021021211 has 4 divisors (see below), whose sum is σ = 26694694952. Its totient is φ = 13347347472.

The previous prime is 20021021203. The next prime is 20021021249. The reversal of 20021021211 is 11212012002.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 20021021211 - 2³ = 20021021203 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20021026211) 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, 3336836866 + ... + 3336836871.

It is an arithmetic number, because the mean of its divisors is an integer number (6673673738).

Almost surely, 2^20021021211 is an apocalyptic number.

20021021211 is a deficient number, since it is larger than the sum of its proper divisors (6673673741).

20021021211 is an equidigital number, since it uses as much as digits as its factorization.

20021021211 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6673673740.

The product of its (nonzero) digits is 16, while the sum is 12.

Adding to 20021021211 its reverse (11212012002), we get a palindrome (31233033213).

The spelling of 20021021211 in words is "twenty billion, twenty-one million, twenty-one thousand, two hundred eleven".