2101100020 has 48 divisors (see below), whose sum is σ = 4576513536. Its totient is φ = 809424000.

The previous prime is 2101100011. The next prime is 2101100059. The reversal of 2101100020 is 200011012.

It is a junction number, because it is equal to n+sod(n) for n = 2101099976 and 2101100012.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 122790 + ... + 138850.

It is an arithmetic number, because the mean of its divisors is an integer number (95344032).

Almost surely, 2^2101100020 is an apocalyptic number.

2101100020 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 2101100020, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2288256768).

2101100020 is an abundant number, since it is smaller than the sum of its proper divisors (2475413516).

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

2101100020 is a wasteful number, since it uses less digits than its factorization.

2101100020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16312 (or 16310 counting only the distinct ones).

The product of its (nonzero) digits is 4, while the sum is 7.

The square root of 2101100020 is about 45837.7575804053. The cubic root of 2101100020 is about 1280.8027232102.

Adding to 2101100020 its reverse (200011012), we get a palindrome (2301111032).

The spelling of 2101100020 in words is "two billion, one hundred one million, one hundred thousand, twenty".