2121055020 has 144 divisors (see below), whose sum is σ = 7364448000. Its totient is φ = 484057728.

The previous prime is 2121054989. The next prime is 2121055037. The reversal of 2121055020 is 205501212.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a junction number, because it is equal to n+sod(n) for n = 2121054984 and 2121055002.

It is an unprimeable number.

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 47 ways as a sum of consecutive naturals, for example, 1414231 + ... + 1415729.

It is an arithmetic number, because the mean of its divisors is an integer number (51142000).

Almost surely, 2^2121055020 is an apocalyptic number.

2121055020 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 2121055020, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3682224000).

2121055020 is an abundant number, since it is smaller than the sum of its proper divisors (5243392980).

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

2121055020 is a wasteful number, since it uses less digits than its factorization.

2121055020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2644 (or 2639 counting only the distinct ones).

The product of its (nonzero) digits is 200, while the sum is 18.

The square root of 2121055020 is about 46054.9130929589. The cubic root of 2121055020 is about 1284.8447217580.

Adding to 2121055020 its reverse (205501212), we get a palindrome (2326556232).

The spelling of 2121055020 in words is "two billion, one hundred twenty-one million, fifty-five thousand, twenty".