2121808500 has 192 divisors, whose sum is σ = 7846325760. Its totient is φ = 484963200.

The previous prime is 2121808463. The next prime is 2121808511. The reversal of 2121808500 is 58081212.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 83274 + ... + 105726.

It is an arithmetic number, because the mean of its divisors is an integer number (40866280).

Almost surely, 2^2121808500 is an apocalyptic number.

2121808500 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 2121808500, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3923162880).

2121808500 is an abundant number, since it is smaller than the sum of its proper divisors (5724517260).

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

2121808500 is a wasteful number, since it uses less digits than its factorization.

2121808500 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22488 (or 22470 counting only the distinct ones).

The product of its (nonzero) digits is 1280, while the sum is 27.

The square root of 2121808500 is about 46063.0926013441. The cubic root of 2121808500 is about 1284.9968457684.

Adding to 2121808500 its reverse (58081212), we get a palindrome (2179889712).

The spelling of 2121808500 in words is "two billion, one hundred twenty-one million, eight hundred eight thousand, five hundred".