1305661 has 8 divisors (see below), whose sum is σ = 1570880. Its totient is φ = 1060128.

The previous prime is 1305659. The next prime is 1305679. The reversal of 1305661 is 1665031.

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

It is a cyclic number.

It is not a de Polignac number, because 1305661 - 2¹ = 1305659 is a prime.

It is a Duffinian number.

1305661 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1305691) 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 7 ways as a sum of consecutive naturals, for example, 4776 + ... + 5041.

It is an arithmetic number, because the mean of its divisors is an integer number (196360).

2^1305661 is an apocalyptic number.

It is an amenable number.

1305661 is a deficient number, since it is larger than the sum of its proper divisors (265219).

1305661 is an equidigital number, since it uses as much as digits as its factorization.

1305661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9843.

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

The square root of 1305661 is about 1142.6552410942. The cubic root of 1305661 is about 109.2974787829.

The spelling of 1305661 in words is "one million, three hundred five thousand, six hundred sixty-one".