1281305 has 8 divisors (see below), whose sum is σ = 1563144. Its totient is φ = 1008000.

The previous prime is 1281283. The next prime is 1281317. The reversal of 1281305 is 5031821.

It can be written as a sum of positive squares in 4 ways, for example, as 80089 + 1201216 = 283^2 + 1096^2 .

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

It is not a de Polignac number, because 1281305 - 2¹⁰ = 1280281 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1796 + ... + 2405.

It is an arithmetic number, because the mean of its divisors is an integer number (195393).

2^1281305 is an apocalyptic number.

It is an amenable number.

1281305 is a deficient number, since it is larger than the sum of its proper divisors (281839).

1281305 is an equidigital number, since it uses as much as digits as its factorization.

1281305 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4267.

The product of its (nonzero) digits is 240, while the sum is 20.

The square root of 1281305 is about 1131.9474369422. The cubic root of 1281305 is about 108.6135912454.

The spelling of 1281305 in words is "one million, two hundred eighty-one thousand, three hundred five".