20111211011111 has 8 divisors (see below), whose sum is σ = 21963692020224. Its totient is φ = 18262761518520.

The previous prime is 20111211011077. The next prime is 20111211011137. The reversal of 20111211011111 is 11111011211102.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20111211011111 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20111211011011) 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 7 ways as a sum of consecutive naturals, for example, 1007868695 + ... + 1007888648.

It is an arithmetic number, because the mean of its divisors is an integer number (2745461502528).

Almost surely, 2^{20111211011111} is an apocalyptic number.

20111211011111 is a deficient number, since it is larger than the sum of its proper divisors (1852481009113).

20111211011111 is a wasteful number, since it uses less digits than its factorization.

20111211011111 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2015758261.

The product of its (nonzero) digits is 4, while the sum is 14.

Adding to 20111211011111 its reverse (11111011211102), we get a palindrome (31222222222213).

The spelling of 20111211011111 in words is "twenty trillion, one hundred eleven billion, two hundred eleven million, eleven thousand, one hundred eleven".