2121389 has 2 divisors, whose sum is σ = 2121390. Its totient is φ = 2121388.

The previous prime is 2121377. The next prime is 2121403. The reversal of 2121389 is 9831212.

2121389 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 2079364 + 42025 = 1442^2 + 205^2 .

It is a cyclic number.

It is not a de Polignac number, because 2121389 - 2⁴ = 2121373 is a prime.

It is a Chen prime.

It is equal to p₁₅₇₂₈₃ and since 2121389 and 157283 have the same sum of digits, it is a Honaker prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2121289) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1060694 + 1060695.

It is an arithmetic number, because the mean of its divisors is an integer number (1060695).

2^2121389 is an apocalyptic number.

It is an amenable number.

2121389 is a deficient number, since it is larger than the sum of its proper divisors (1).

2121389 is an equidigital number, since it uses as much as digits as its factorization.

2121389 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 864, while the sum is 26.

The square root of 2121389 is about 1456.4988843113. The cubic root of 2121389 is about 128.4912155168.

The spelling of 2121389 in words is "two million, one hundred twenty-one thousand, three hundred eighty-nine".