1605442 has 4 divisors (see below), whose sum is σ = 2408166. Its totient is φ = 802720.

The previous prime is 1605433. The next prime is 1605509. The reversal of 1605442 is 2445061.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 2445061 = 23 ⋅106307.

It can be written as a sum of positive squares in only one way, i.e., 1394761 + 210681 = 1181^2 + 459^2 .

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 an unprimeable number.

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, 401359 + ... + 401362.

2^1605442 is an apocalyptic number.

1605442 is a deficient number, since it is larger than the sum of its proper divisors (802724).

1605442 is an equidigital number, since it uses as much as digits as its factorization.

1605442 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 802723.

The product of its (nonzero) digits is 960, while the sum is 22.

The square root of 1605442 is about 1267.0603774091. The cubic root of 1605442 is about 117.0931636764.

The spelling of 1605442 in words is "one million, six hundred five thousand, four hundred forty-two".