2121020205 has 16 divisors (see below), whose sum is σ = 3451152960. Its totient is φ = 1112037248.

The previous prime is 2121020201. The next prime is 2121020219. The reversal of 2121020205 is 5020201212.

It is a cyclic number.

It is not a de Polignac number, because 2121020205 - 2² = 2121020201 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (15).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2121020201) 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, 1197432 + ... + 1199201.

It is an arithmetic number, because the mean of its divisors is an integer number (215697060).

Almost surely, 2^2121020205 is an apocalyptic number.

It is an amenable number.

2121020205 is a deficient number, since it is larger than the sum of its proper divisors (1330132755).

2121020205 is a wasteful number, since it uses less digits than its factorization.

2121020205 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2396700.

The product of its (nonzero) digits is 80, while the sum is 15.

The square root of 2121020205 is about 46054.5351187047. The cubic root of 2121020205 is about 1284.8376919052.

Adding to 2121020205 its reverse (5020201212), we get a palindrome (7141221417).

The spelling of 2121020205 in words is "two billion, one hundred twenty-one million, twenty thousand, two hundred five".