1311281 has 4 divisors (see below), whose sum is σ = 1316964. Its totient is φ = 1305600.

The previous prime is 1311263. The next prime is 1311287. The reversal of 1311281 is 1821131.

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 970225 + 341056 = 985^2 + 584^2 .

It is a cyclic number.

It is not a de Polignac number, because 1311281 - 2⁶ = 1311217 is a prime.

It is a super-2 number, since 2×1311281² = 3438915721922, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1311287) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2480 + ... + 2961.

It is an arithmetic number, because the mean of its divisors is an integer number (329241).

2^1311281 is an apocalyptic number.

It is an amenable number.

1311281 is a deficient number, since it is larger than the sum of its proper divisors (5683).

1311281 is an equidigital number, since it uses as much as digits as its factorization.

1311281 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5682.

The product of its digits is 48, while the sum is 17.

The square root of 1311281 is about 1145.1117849363. Note that the first 3 decimals coincide. The cubic root of 1311281 is about 109.4540719102.

The spelling of 1311281 in words is "one million, three hundred eleven thousand, two hundred eighty-one".