2121002020 has 48 divisors (see below), whose sum is σ = 4643444736. Its totient is φ = 812880000.

The previous prime is 2121002011. The next prime is 2121002027. The reversal of 2121002020 is 202001212.

It is a Harshad number since it is a multiple of its sum of digits (10).

It is a junction number, because it is equal to n+sod(n) for n = 2121001988 and 2121002006.

It is not an unprimeable number, because it can be changed into a prime (2121002027) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 45685 + ... + 79555.

It is an arithmetic number, because the mean of its divisors is an integer number (96738432).

Almost surely, 2^2121002020 is an apocalyptic number.

2121002020 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 2121002020, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2321722368).

2121002020 is an abundant number, since it is smaller than the sum of its proper divisors (2522442716).

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

2121002020 is a wasteful number, since it uses less digits than its factorization.

2121002020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 34012 (or 34010 counting only the distinct ones).

The product of its (nonzero) digits is 16, while the sum is 10.

The square root of 2121002020 is about 46054.3376892991. The cubic root of 2121002020 is about 1284.8340199552.

Adding to 2121002020 its reverse (202001212), we get a palindrome (2323003232).

The spelling of 2121002020 in words is "two billion, one hundred twenty-one million, two thousand, twenty".