20012100111 has 32 divisors (see below), whose sum is σ = 30620747520. Its totient is φ = 12909268512.

The previous prime is 20012100079. The next prime is 20012100133. The reversal of 20012100111 is 11100121002.

It is a happy number.

It is not a de Polignac number, because 20012100111 - 2⁵ = 20012100079 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (9).

It is a junction number, because it is equal to n+sod(n) for n = 20012100093 and 20012100102.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20012100011) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 43681 + ... + 204773.

It is an arithmetic number, because the mean of its divisors is an integer number (956898360).

Almost surely, 2^20012100111 is an apocalyptic number.

20012100111 is a deficient number, since it is larger than the sum of its proper divisors (10608647409).

20012100111 is a wasteful number, since it uses less digits than its factorization.

20012100111 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 161252 (or 161246 counting only the distinct ones).

The product of its (nonzero) digits is 4, while the sum is 9.

Adding to 20012100111 its reverse (11100121002), we get a palindrome (31112221113).

The spelling of 20012100111 in words is "twenty billion, twelve million, one hundred thousand, one hundred eleven".