1305249805 has 4 divisors (see below), whose sum is σ = 1566299772. Its totient is φ = 1044199840.

The previous prime is 1305249733. The next prime is 1305249811. The reversal of 1305249805 is 5089425031.

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 172186884 + 1133062921 = 13122^2 + 33661^2 .

It is not a de Polignac number, because 1305249805 - 2⁹ = 1305249293 is a prime.

It is a Duffinian number.

It is a congruent 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, 130524976 + ... + 130524985.

It is an arithmetic number, because the mean of its divisors is an integer number (391574943).

Almost surely, 2^1305249805 is an apocalyptic number.

It is an amenable number.

1305249805 is a deficient number, since it is larger than the sum of its proper divisors (261049967).

1305249805 is an equidigital number, since it uses as much as digits as its factorization.

1305249805 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 261049966.

The product of its (nonzero) digits is 43200, while the sum is 37.

The square root of 1305249805 is about 36128.2411002805. The cubic root of 1305249805 is about 1092.8600380444.

The spelling of 1305249805 in words is "one billion, three hundred five million, two hundred forty-nine thousand, eight hundred five".