1280289 has 4 divisors (see below), whose sum is σ = 1707056. Its totient is φ = 853524.

The previous prime is 1280281. The next prime is 1280291. The reversal of 1280289 is 9820821.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 1280289 - 2³ = 1280281 is a prime.

It is a D-number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1280281) 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, 213379 + ... + 213384.

It is an arithmetic number, because the mean of its divisors is an integer number (426764).

2^1280289 is an apocalyptic number.

It is an amenable number.

1280289 is a deficient number, since it is larger than the sum of its proper divisors (426767).

1280289 is an equidigital number, since it uses as much as digits as its factorization.

1280289 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 426766.

The product of its (nonzero) digits is 2304, while the sum is 30.

The square root of 1280289 is about 1131.4985638524. The cubic root of 1280289 is about 108.5848755769.

The spelling of 1280289 in words is "one million, two hundred eighty thousand, two hundred eighty-nine".