1609945 has 8 divisors (see below), whose sum is σ = 1945800. Its totient is φ = 1278720.

The previous prime is 1609913. The next prime is 1609969. The reversal of 1609945 is 5499061.

It can be written as a sum of positive squares in 4 ways, for example, as 44944 + 1565001 = 212^2 + 1251^2 .

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

It is not a de Polignac number, because 1609945 - 2⁵ = 1609913 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1609945.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 336 + ... + 1825.

It is an arithmetic number, because the mean of its divisors is an integer number (243225).

2^1609945 is an apocalyptic number.

It is an amenable number.

1609945 is a deficient number, since it is larger than the sum of its proper divisors (335855).

1609945 is a wasteful number, since it uses less digits than its factorization.

1609945 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2315.

The product of its (nonzero) digits is 9720, while the sum is 34.

The square root of 1609945 is about 1268.8360808237. The cubic root of 1609945 is about 117.2025371519.

Subtracting from 1609945 its product of nonzero digits (9720), we obtain a square (1600225 = 1265²).

The spelling of 1609945 in words is "one million, six hundred nine thousand, nine hundred forty-five".