20111202111 has 64 divisors (see below), whose sum is σ = 36976536576. Its totient is φ = 9383040000.

The previous prime is 20111202109. The next prime is 20111202127. The reversal of 20111202111 is 11120211102.

It is not a de Polignac number, because 20111202111 - 2¹ = 20111202109 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20111202131) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 20611 + ... + 201611.

It is an arithmetic number, because the mean of its divisors is an integer number (577758384).

Almost surely, 2^20111202111 is an apocalyptic number.

20111202111 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

20111202111 is a deficient number, since it is larger than the sum of its proper divisors (16865334465).

20111202111 is a wasteful number, since it uses less digits than its factorization.

20111202111 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 181072.

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

Adding to 20111202111 its reverse (11120211102), we get a palindrome (31231413213).

It can be divided in two parts, 20111 and 202111, that added together give a palindrome (222222).

The spelling of 20111202111 in words is "twenty billion, one hundred eleven million, two hundred two thousand, one hundred eleven".