2101220111 has 16 divisors (see below), whose sum is σ = 2302655040. Its totient is φ = 1909432320.

The previous prime is 2101220087. The next prime is 2101220167. The reversal of 2101220111 is 1110221012.

It is not a de Polignac number, because 2101220111 - 2¹⁸ = 2100957967 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 2101220092 and 2101220101.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2101220171) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 52070 + ... + 83148.

It is an arithmetic number, because the mean of its divisors is an integer number (143915940).

Almost surely, 2^2101220111 is an apocalyptic number.

2101220111 is a deficient number, since it is larger than the sum of its proper divisors (201434929).

2101220111 is a wasteful number, since it uses less digits than its factorization.

2101220111 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 31234.

The product of its (nonzero) digits is 8, while the sum is 11.

The square root of 2101220111 is about 45839.0675188752. The cubic root of 2101220111 is about 1280.8271247059.

Adding to 2101220111 its reverse (1110221012), we get a palindrome (3211441123).

Subtracting from 2101220111 its reverse (1110221012), we obtain a palindrome (990999099).

The spelling of 2101220111 in words is "two billion, one hundred one million, two hundred twenty thousand, one hundred eleven".