2181442 has 4 divisors (see below), whose sum is σ = 3272166. Its totient is φ = 1090720.

The previous prime is 2181419. The next prime is 2181449. The reversal of 2181442 is 2441812.

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

It can be written as a sum of positive squares in only one way, i.e., 1798281 + 383161 = 1341^2 + 619^2 .

It is a Smith number, since the sum of its digits (22) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is not an unprimeable number, because it can be changed into a prime (2181449) 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, 545359 + ... + 545362.

2^2181442 is an apocalyptic number.

2181442 is a deficient number, since it is larger than the sum of its proper divisors (1090724).

2181442 is a wasteful number, since it uses less digits than its factorization.

2181442 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1090723.

The product of its digits is 512, while the sum is 22.

The square root of 2181442 is about 1476.9705481153. The cubic root of 2181442 is about 129.6924088818.

The spelling of 2181442 in words is "two million, one hundred eighty-one thousand, four hundred forty-two".