2121869 has 2 divisors, whose sum is σ = 2121870. Its totient is φ = 2121868.

The previous prime is 2121853. The next prime is 2121877. The reversal of 2121869 is 9681212.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1716100 + 405769 = 1310^2 + 637^2 .

It is a cyclic number.

It is not a de Polignac number, because 2121869 - 2⁴ = 2121853 is a prime.

It is a super-2 number, since 2×2121869² = 9004656106322, which contains 22 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2121809) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1060934 + 1060935.

It is an arithmetic number, because the mean of its divisors is an integer number (1060935).

2^2121869 is an apocalyptic number.

It is an amenable number.

2121869 is a deficient number, since it is larger than the sum of its proper divisors (1).

2121869 is an equidigital number, since it uses as much as digits as its factorization.

2121869 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1728, while the sum is 29.

The square root of 2121869 is about 1456.6636536964. The cubic root of 2121869 is about 128.5009058867.

The spelling of 2121869 in words is "two million, one hundred twenty-one thousand, eight hundred sixty-nine".