2189661 has 8 divisors (see below), whose sum is σ = 2937120. Its totient is φ = 1450992.

The previous prime is 2189647. The next prime is 2189699. The reversal of 2189661 is 1669812.

2189661 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 2189661 - 2⁷ = 2189533 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2189461) 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 7 ways as a sum of consecutive naturals, for example, 1591 + ... + 2628.

It is an arithmetic number, because the mean of its divisors is an integer number (367140).

2^2189661 is an apocalyptic number.

It is an amenable number.

2189661 is a deficient number, since it is larger than the sum of its proper divisors (747459).

2189661 is a wasteful number, since it uses less digits than its factorization.

2189661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4395.

The product of its digits is 5184, while the sum is 33.

The square root of 2189661 is about 1479.7503167764. The cubic root of 2189661 is about 129.8550850673.

It can be divided in two parts, 2189 and 661, that added together give a triangular number (2850 = T₇₅).

The spelling of 2189661 in words is "two million, one hundred eighty-nine thousand, six hundred sixty-one".