2121013020 has 144 divisors (see below), whose sum is σ = 7146951840. Its totient is φ = 468066816.

The previous prime is 2121012979. The next prime is 2121013021. The reversal of 2121013020 is 203101212.

It is a Harshad number since it is a multiple of its sum of digits (12).

It is a junction number, because it is equal to n+sod(n) for n = 2121012987 and 2121013005.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2121013021) 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 47 ways as a sum of consecutive naturals, for example, 72822 + ... + 97698.

It is an arithmetic number, because the mean of its divisors is an integer number (49631610).

Almost surely, 2^2121013020 is an apocalyptic number.

2121013020 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 2121013020, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3573475920).

2121013020 is an abundant number, since it is smaller than the sum of its proper divisors (5025938820).

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

2121013020 is a wasteful number, since it uses less digits than its factorization.

2121013020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 24932 (or 24923 counting only the distinct ones).

The product of its (nonzero) digits is 24, while the sum is 12.

The square root of 2121013020 is about 46054.4571132914. The cubic root of 2121013020 is about 1284.8362410988.

Adding to 2121013020 its reverse (203101212), we get a palindrome (2324114232).

The spelling of 2121013020 in words is "two billion, one hundred twenty-one million, thirteen thousand, twenty".