20011223111 has 24 divisors (see below), whose sum is σ = 23061314304. Its totient is φ = 17218509840.

The previous prime is 20011223101. The next prime is 20011223131. The reversal of 20011223111 is 11132211002.

It is a de Polignac number, because none of the positive numbers 2^k-20011223111 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 (20011223101) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 6618146 + ... + 6621168.

It is an arithmetic number, because the mean of its divisors is an integer number (960888096).

Almost surely, 2^20011223111 is an apocalyptic number.

20011223111 is a deficient number, since it is larger than the sum of its proper divisors (3050091193).

20011223111 is a wasteful number, since it uses less digits than its factorization.

20011223111 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4739 (or 4720 counting only the distinct ones).

The product of its (nonzero) digits is 24, while the sum is 14.

Adding to 20011223111 its reverse (11132211002), we get a palindrome (31143434113).

The spelling of 20011223111 in words is "twenty billion, eleven million, two hundred twenty-three thousand, one hundred eleven".