1306561 has 4 divisors (see below), whose sum is σ = 1363392. Its totient is φ = 1249732.

The previous prime is 1306541. The next prime is 1306589. The reversal of 1306561 is 1656031.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1306561 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1306541) 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, 28381 + ... + 28426.

It is an arithmetic number, because the mean of its divisors is an integer number (340848).

2^1306561 is an apocalyptic number.

It is an amenable number.

1306561 is a deficient number, since it is larger than the sum of its proper divisors (56831).

1306561 is an equidigital number, since it uses as much as digits as its factorization.

1306561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 56830.

The product of its (nonzero) digits is 540, while the sum is 22.

The square root of 1306561 is about 1143.0489928258. The cubic root of 1306561 is about 109.3225861520.

The spelling of 1306561 in words is "one million, three hundred six thousand, five hundred sixty-one".