20021111211 has 4 divisors (see below), whose sum is σ = 26694814952. Its totient is φ = 13347407472.

The previous prime is 20021111161. The next prime is 20021111239. The reversal of 20021111211 is 11211112002.

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

It is not a de Polignac number, because 20021111211 - 2¹³ = 20021103019 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20021111251) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3336851866 + ... + 3336851871.

It is an arithmetic number, because the mean of its divisors is an integer number (6673703738).

Almost surely, 2^20021111211 is an apocalyptic number.

20021111211 is a deficient number, since it is larger than the sum of its proper divisors (6673703741).

20021111211 is an equidigital number, since it uses as much as digits as its factorization.

20021111211 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6673703740.

The product of its (nonzero) digits is 8, while the sum is 12.

Adding to 20021111211 its reverse (11211112002), we get a palindrome (31232223213).

The spelling of 20021111211 in words is "twenty billion, twenty-one million, one hundred eleven thousand, two hundred eleven".