2189779 has 4 divisors (see below), whose sum is σ = 2193640. Its totient is φ = 2185920.

The previous prime is 2189767. The next prime is 2189783. The reversal of 2189779 is 9779812.

It is a happy number.

2189779 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 2189779 - 2⁹ = 2189267 is a prime.

It is a Duffinian number.

2189779 is a lucky number.

It is not an unprimeable number, because it can be changed into a prime (2189729) 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 in 3 ways as a sum of consecutive naturals, for example, 894 + ... + 2275.

It is an arithmetic number, because the mean of its divisors is an integer number (548410).

2^2189779 is an apocalyptic number.

2189779 is a deficient number, since it is larger than the sum of its proper divisors (3861).

2189779 is an equidigital number, since it uses as much as digits as its factorization.

2189779 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3860.

The product of its digits is 63504, while the sum is 43.

The square root of 2189779 is about 1479.7901878307. The cubic root of 2189779 is about 129.8574176391.

The spelling of 2189779 in words is "two million, one hundred eighty-nine thousand, seven hundred seventy-nine".