2121022100 has 18 divisors (see below), whose sum is σ = 4602618174. Its totient is φ = 848408800.

The previous prime is 2121022061. The next prime is 2121022103. The reversal of 2121022100 is 12201212.

It is a happy number.

It can be written as a sum of positive squares in 3 ways, for example, as 23931664 + 2097090436 = 4892^2 + 45794^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2121022103) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 10605011 + ... + 10605210.

Almost surely, 2^2121022100 is an apocalyptic number.

2121022100 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

2121022100 is an abundant number, since it is smaller than the sum of its proper divisors (2481596074).

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

2121022100 is a wasteful number, since it uses less digits than its factorization.

2121022100 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21210235 (or 21210228 counting only the distinct ones).

The product of its (nonzero) digits is 16, while the sum is 11.

The square root of 2121022100 is about 46054.5556921354. Note that the first 3 decimals coincide. The cubic root of 2121022100 is about 1284.8380745460.

Adding to 2121022100 its reverse (12201212), we get a palindrome (2133223312).

The spelling of 2121022100 in words is "two billion, one hundred twenty-one million, twenty-two thousand, one hundred".