1306505 has 4 divisors (see below), whose sum is σ = 1567812. Its totient is φ = 1045200.

The previous prime is 1306499. The next prime is 1306517. The reversal of 1306505 is 5056031.

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

It can be written as a sum of positive squares in 2 ways, for example, as 546121 + 760384 = 739^2 + 872^2 .

It is not a de Polignac number, because 1306505 - 2⁴ = 1306489 is a prime.

It is an Ulam number.

It is a Duffinian number.

It is a Curzon number.

It is an unprimeable number.

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, 130646 + ... + 130655.

It is an arithmetic number, because the mean of its divisors is an integer number (391953).

2^1306505 is an apocalyptic number.

It is an amenable number.

1306505 is a deficient number, since it is larger than the sum of its proper divisors (261307).

1306505 is an equidigital number, since it uses as much as digits as its factorization.

1306505 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 261306.

The product of its (nonzero) digits is 450, while the sum is 20.

The square root of 1306505 is about 1143.0244966754. The cubic root of 1306505 is about 109.3210242521.

It can be divided in two parts, 130 and 6505, that multiplied together give a triangular number (845650 = T₁₃₀₀).

The spelling of 1306505 in words is "one million, three hundred six thousand, five hundred five".