1809442 has 4 divisors (see below), whose sum is σ = 2714166. Its totient is φ = 904720.

The previous prime is 1809421. The next prime is 1809449. The reversal of 1809442 is 2449081.

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., 1540081 + 269361 = 1241^2 + 519^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 1809442.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1809449) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 452359 + ... + 452362.

2^1809442 is an apocalyptic number.

1809442 is a deficient number, since it is larger than the sum of its proper divisors (904724).

1809442 is an equidigital number, since it uses as much as digits as its factorization.

1809442 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 904723.

The product of its (nonzero) digits is 2304, while the sum is 28.

The square root of 1809442 is about 1345.1550096550. The cubic root of 1809442 is about 121.8563659436.

The spelling of 1809442 in words is "one million, eight hundred nine thousand, four hundred forty-two".