2188909 has 2 divisors, whose sum is σ = 2188910. Its totient is φ = 2188908.

The previous prime is 2188877. The next prime is 2188913. The reversal of 2188909 is 9098812.

2188909 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1729225 + 459684 = 1315^2 + 678^2 .

It is a cyclic number.

It is not a de Polignac number, because 2188909 - 2⁵ = 2188877 is a prime.

It is a super-2 number, since 2×2188909² = 9582645220562, which contains 22 as substring.

It is a Chen prime.

2188909 is a lucky number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2188919) 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, 1094454 + 1094455.

It is an arithmetic number, because the mean of its divisors is an integer number (1094455).

2^2188909 is an apocalyptic number.

It is an amenable number.

2188909 is a deficient number, since it is larger than the sum of its proper divisors (1).

2188909 is an equidigital number, since it uses as much as digits as its factorization.

2188909 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 10368, while the sum is 37.

The square root of 2188909 is about 1479.4961980350. The cubic root of 2188909 is about 129.8402178946.

Subtracting 2188909 from its reverse (9098812), we obtain a triangular number (6909903 = T₃₇₁₇).

The spelling of 2188909 in words is "two million, one hundred eighty-eight thousand, nine hundred nine".