1280909 has 6 divisors (see below), whose sum is σ = 1490094. Its totient is φ = 1097880.

The previous prime is 1280887. The next prime is 1280921. The reversal of 1280909 is 9090821.

It can be written as a sum of positive squares in only one way, i.e., 1177225 + 103684 = 1085^2 + 322^2 .

It is not a de Polignac number, because 1280909 - 2²⁰ = 232333 is a prime.

It is a Duffinian number.

1280909 is a modest number, since divided by 909 gives 128 as remainder.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1280969) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 13022 + ... + 13119.

It is an arithmetic number, because the mean of its divisors is an integer number (248349).

2^1280909 is an apocalyptic number.

It is an amenable number.

1280909 is a deficient number, since it is larger than the sum of its proper divisors (209185).

1280909 is an equidigital number, since it uses as much as digits as its factorization.

1280909 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 26155 (or 26148 counting only the distinct ones).

The product of its (nonzero) digits is 1296, while the sum is 29.

The square root of 1280909 is about 1131.7725036420. The cubic root of 1280909 is about 108.6024007238.

The spelling of 1280909 in words is "one million, two hundred eighty thousand, nine hundred nine".