2120021100 has 180 divisors, whose sum is σ = 6908531784. Its totient is φ = 562360320.

The previous prime is 2120021093. The next prime is 2120021107. The reversal of 2120021100 is 11200212.

It is an interprime number because it is at equal distance from previous prime (2120021093) and next prime (2120021107).

It is a tau number, because it is divible by the number of its divisors (180).

It is a Harshad number since it is a multiple of its sum of digits (9).

It is not an unprimeable number, because it can be changed into a prime (2120021107) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 59 ways as a sum of consecutive naturals, for example, 1838124 + ... + 1839276.

Almost surely, 2^2120021100 is an apocalyptic number.

2120021100 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 2120021100, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3454265892).

2120021100 is an abundant number, since it is smaller than the sum of its proper divisors (4788510684).

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

2120021100 is a wasteful number, since it uses less digits than its factorization.

2120021100 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1406 (or 1390 counting only the distinct ones).

The product of its (nonzero) digits is 8, while the sum is 9.

The square root of 2120021100 is about 46043.6868636733. The cubic root of 2120021100 is about 1284.6359196052.

Adding to 2120021100 its reverse (11200212), we get a palindrome (2131221312).

The spelling of 2120021100 in words is "two billion, one hundred twenty million, twenty-one thousand, one hundred".