2121000020 has 48 divisors (see below), whose sum is σ = 4788322560. Its totient is φ = 786639744.

The previous prime is 2120999989. The next prime is 2121000023. The reversal of 2121000020 is 200001212.

It is a junction number, because it is equal to n+sod(n) for n = 2120999971 and 2121000007.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2121000023) 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, 41519 + ... + 77238.

It is an arithmetic number, because the mean of its divisors is an integer number (99756720).

Almost surely, 2^2121000020 is an apocalyptic number.

2121000020 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

2121000020 is an abundant number, since it is smaller than the sum of its proper divisors (2667322540).

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

2121000020 is a wasteful number, since it uses less digits than its factorization.

2121000020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 118832 (or 118830 counting only the distinct ones).

The product of its (nonzero) digits is 8, while the sum is 8.

The square root of 2121000020 is about 46054.3159758127. The cubic root of 2121000020 is about 1284.8336161101.

Adding to 2121000020 its reverse (200001212), we get a palindrome (2321001232).

The spelling of 2121000020 in words is "two billion, one hundred twenty-one million, twenty", and thus it is an aban number.