20110121111 has 4 divisors (see below), whose sum is σ = 20119057224. Its totient is φ = 20101185000.

The previous prime is 20110121107. The next prime is 20110121131. The reversal of 20110121111 is 11112101102.

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

It is a cyclic number.

It is not a de Polignac number, because 20110121111 - 2² = 20110121107 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 20110121092 and 20110121101.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20110121131) 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, 4464680 + ... + 4469181.

It is an arithmetic number, because the mean of its divisors is an integer number (5029764306).

Almost surely, 2^20110121111 is an apocalyptic number.

20110121111 is a deficient number, since it is larger than the sum of its proper divisors (8936113).

20110121111 is an equidigital number, since it uses as much as digits as its factorization.

20110121111 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8936112.

The product of its (nonzero) digits is 4, while the sum is 11.

Adding to 20110121111 its reverse (11112101102), we get a palindrome (31222222213).

The spelling of 20110121111 in words is "twenty billion, one hundred ten million, one hundred twenty-one thousand, one hundred eleven".