2121020989 has 2 divisors, whose sum is σ = 2121020990. Its totient is φ = 2121020988.

The previous prime is 2121020983. The next prime is 2121021013. The reversal of 2121020989 is 9890201212.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1786752900 + 334268089 = 42270^2 + 18283^2 .

It is a cyclic number.

It is not a de Polignac number, because 2121020989 - 2³ = 2121020981 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2121020981) by changing a digit.

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 as a sum of consecutive naturals, namely, 1060510494 + 1060510495.

It is an arithmetic number, because the mean of its divisors is an integer number (1060510495).

Almost surely, 2^2121020989 is an apocalyptic number.

It is an amenable number.

2121020989 is a deficient number, since it is larger than the sum of its proper divisors (1).

2121020989 is an equidigital number, since it uses as much as digits as its factorization.

2121020989 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 5184, while the sum is 34.

The square root of 2121020989 is about 46054.5436303520. The cubic root of 2121020989 is about 1284.8378502115.

It can be divided in two parts, 212 and 1020989, that added together give a palindrome (1021201).

The spelling of 2121020989 in words is "two billion, one hundred twenty-one million, twenty thousand, nine hundred eighty-nine".