1305684985 has 12 divisors (see below), whose sum is σ = 1722210084. Its totient is φ = 949588640.

The previous prime is 1305684943. The next prime is 1305685019. The reversal of 1305684985 is 5894865031.

It can be written as a sum of positive squares in 2 ways, for example, as 1034522896 + 271162089 = 32164^2 + 16467^2 .

It is not a de Polignac number, because 1305684985 - 2¹⁵ = 1305652217 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1078474 + ... + 1079683.

It is an arithmetic number, because the mean of its divisors is an integer number (143517507).

Almost surely, 2^1305684985 is an apocalyptic number.

It is an amenable number.

1305684985 is a deficient number, since it is larger than the sum of its proper divisors (416525099).

1305684985 is a wasteful number, since it uses less digits than its factorization.

1305684985 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2158184 (or 2158173 counting only the distinct ones).

The product of its (nonzero) digits is 1036800, while the sum is 49.

The square root of 1305684985 is about 36134.2633106031. The cubic root of 1305684985 is about 1092.9814804391.

The spelling of 1305684985 in words is "one billion, three hundred five million, six hundred eighty-four thousand, nine hundred eighty-five".