20012311111 has 4 divisors (see below), whose sum is σ = 21551719672. Its totient is φ = 18472902552.

The previous prime is 20012311103. The next prime is 20012311129. The reversal of 20012311111 is 11111321002.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 20012311111 - 2³ = 20012311103 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (13), and also a Moran number because the ratio is a prime number: 1539408547 = 20012311111 / (2 + 0 + 0 + 1 + 2 + 3 + 1 + 1 + 1 + 1 + 1).

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 20012311091 and 20012311100.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20012311211) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 769704261 + ... + 769704286.

It is an arithmetic number, because the mean of its divisors is an integer number (5387929918).

Almost surely, 2^20012311111 is an apocalyptic number.

20012311111 is a deficient number, since it is larger than the sum of its proper divisors (1539408561).

20012311111 is a wasteful number, since it uses less digits than its factorization.

20012311111 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1539408560.

The product of its (nonzero) digits is 12, while the sum is 13.

Adding to 20012311111 its reverse (11111321002), we get a palindrome (31123632113).

The spelling of 20012311111 in words is "twenty billion, twelve million, three hundred eleven thousand, one hundred eleven".