1305445 has 4 divisors (see below), whose sum is σ = 1566540. Its totient is φ = 1044352.

The previous prime is 1305431. The next prime is 1305449. The reversal of 1305445 is 5445031.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 5445031 = 37 ⋅147163.

It can be written as a sum of positive squares in 2 ways, for example, as 923521 + 381924 = 961^2 + 618^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1305445 is a prime.

It is an Ulam number.

1305445 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1305449) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 130540 + ... + 130549.

It is an arithmetic number, because the mean of its divisors is an integer number (391635).

2^1305445 is an apocalyptic number.

It is an amenable number.

1305445 is a deficient number, since it is larger than the sum of its proper divisors (261095).

1305445 is an equidigital number, since it uses as much as digits as its factorization.

1305445 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 261094.

The product of its (nonzero) digits is 1200, while the sum is 22.

The square root of 1305445 is about 1142.5607204871. The cubic root of 1305445 is about 109.2914512976.

The spelling of 1305445 in words is "one million, three hundred five thousand, four hundred forty-five".