20111002111 has 4 divisors (see below), whose sum is σ = 20114883000. Its totient is φ = 20107121224.

The previous prime is 20111002097. The next prime is 20111002117. The reversal of 20111002111 is 11120011102.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 11120011102 = 2 ⋅5560005551.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20111002111 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 (20111002117) 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, 1932661 + ... + 1943038.

It is an arithmetic number, because the mean of its divisors is an integer number (5028720750).

Almost surely, 2^20111002111 is an apocalyptic number.

20111002111 is a deficient number, since it is larger than the sum of its proper divisors (3880889).

20111002111 is an equidigital number, since it uses as much as digits as its factorization.

20111002111 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3880888.

The product of its (nonzero) digits is 4, while the sum is 10.

Adding to 20111002111 its reverse (11120011102), we get a palindrome (31231013213).

The spelling of 20111002111 in words is "twenty billion, one hundred eleven million, two thousand, one hundred eleven".