1287281 has 4 divisors (see below), whose sum is σ = 1331700. Its totient is φ = 1242864.

The previous prime is 1287239. The next prime is 1287289. The reversal of 1287281 is 1827821.

1287281 is nontrivially palindromic in base 9.

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 1032256 + 255025 = 1016^2 + 505^2 .

It is a cyclic number.

It is not a de Polignac number, because 1287281 - 2⁶ = 1287217 is a prime.

It is a super-2 number, since 2×1287281² = 3314184745922, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (29), and also a Moran number because the ratio is a prime number: 44389 = 1287281 / (1 + 2 + 8 + 7 + 2 + 8 + 1).

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (1287289) 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, 22166 + ... + 22223.

It is an arithmetic number, because the mean of its divisors is an integer number (332925).

2^1287281 is an apocalyptic number.

It is an amenable number.

1287281 is a deficient number, since it is larger than the sum of its proper divisors (44419).

1287281 is an equidigital number, since it uses as much as digits as its factorization.

1287281 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 44418.

The product of its digits is 1792, while the sum is 29.

The square root of 1287281 is about 1134.5840647568. The cubic root of 1287281 is about 108.7821871519.

The spelling of 1287281 in words is "one million, two hundred eighty-seven thousand, two hundred eighty-one".