2100111220 has 24 divisors (see below), whose sum is σ = 4493447784. Its totient is φ = 824194176.

The previous prime is 2100111203. The next prime is 2100111239. The reversal of 2100111220 is 221110012.

It can be written as a sum of positive squares in 4 ways, for example, as 441504144 + 1658607076 = 21012^2 + 40726^2 .

It is a Harshad number since it is a multiple of its sum of digits (10).

It is a junction number, because it is equal to n+sod(n) for n = 2100111197 and 2100111206.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 989559 + ... + 991678.

It is an arithmetic number, because the mean of its divisors is an integer number (187226991).

Almost surely, 2^2100111220 is an apocalyptic number.

2100111220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

2100111220 is an abundant number, since it is smaller than the sum of its proper divisors (2393336564).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

2100111220 is a wasteful number, since it uses less digits than its factorization.

2100111220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1981299 (or 1981297 counting only the distinct ones).

The product of its (nonzero) digits is 8, while the sum is 10.

The square root of 2100111220 is about 45826.9704431790. The cubic root of 2100111220 is about 1280.6017718923.

Adding to 2100111220 its reverse (221110012), we get a palindrome (2321221232).

The spelling of 2100111220 in words is "two billion, one hundred million, one hundred eleven thousand, two hundred twenty".