2289781 has 12 divisors (see below), whose sum is σ = 2628612. Its totient is φ = 1986816.

The previous prime is 2289779. The next prime is 2289803. The reversal of 2289781 is 1879822.

2289781 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 6 ways, for example, as 140625 + 2149156 = 375^2 + 1466^2 .

It is not a de Polignac number, because 2289781 - 2¹ = 2289779 is a prime.

It is a super-2 number, since 2×2289781² = 10486194055922, which contains 22 as substring.

It is a Duffinian number.

2289781 is a lucky number.

It is a self number, because there is not a number n which added to its sum of digits gives 2289781.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2289751) 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 11 ways as a sum of consecutive naturals, for example, 2475 + ... + 3271.

It is an arithmetic number, because the mean of its divisors is an integer number (219051).

2^2289781 is an apocalyptic number.

It is an amenable number.

2289781 is a deficient number, since it is larger than the sum of its proper divisors (338831).

2289781 is a wasteful number, since it uses less digits than its factorization.

2289781 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 840 (or 827 counting only the distinct ones).

The product of its digits is 16128, while the sum is 37.

The square root of 2289781 is about 1513.2022336753. The cubic root of 2289781 is about 131.8048271125.

The spelling of 2289781 in words is "two million, two hundred eighty-nine thousand, seven hundred eighty-one".