20011212211 has 4 divisors (see below), whose sum is σ = 20043645912. Its totient is φ = 19978778512.

The previous prime is 20011212197. The next prime is 20011212241. The reversal of 20011212211 is 11221211002.

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 20011212211 - 2⁷ = 20011212083 is a prime.

It is a super-2 number, since 2×20011212211² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 20011212191 and 20011212200.

It is not an unprimeable number, because it can be changed into a prime (20011212241) 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, 16215925 + ... + 16217158.

It is an arithmetic number, because the mean of its divisors is an integer number (5010911478).

Almost surely, 2^20011212211 is an apocalyptic number.

20011212211 is a deficient number, since it is larger than the sum of its proper divisors (32433701).

20011212211 is an equidigital number, since it uses as much as digits as its factorization.

20011212211 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 32433700.

The product of its (nonzero) digits is 16, while the sum is 13.

Adding to 20011212211 its reverse (11221211002), we get a palindrome (31232423213).

The spelling of 20011212211 in words is "twenty billion, eleven million, two hundred twelve thousand, two hundred eleven".