20001111211211 has 4 divisors (see below), whose sum is σ = 21539658227472. Its totient is φ = 18462564194952.

The previous prime is 20001111211199. The next prime is 20001111211399. The reversal of 20001111211211 is 11211211110002.

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 20001111211211 - 2⁴² = 15603064700107 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20001111261211) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 769273508111 + ... + 769273508136.

It is an arithmetic number, because the mean of its divisors is an integer number (5384914556868).

Almost surely, 2^{20001111211211} is an apocalyptic number.

20001111211211 is a deficient number, since it is larger than the sum of its proper divisors (1538547016261).

20001111211211 is a wasteful number, since it uses less digits than its factorization.

20001111211211 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1538547016260.

The product of its (nonzero) digits is 8, while the sum is 14.

Adding to 20001111211211 its reverse (11211211110002), we get a palindrome (31212322321213).

The spelling of 20001111211211 in words is "twenty trillion, one billion, one hundred eleven million, two hundred eleven thousand, two hundred eleven".