1280005 has 8 divisors (see below), whose sum is σ = 1562400. Its totient is φ = 1006416.

The previous prime is 1279997. The next prime is 1280023. The reversal of 1280005 is 5000821.

It is a happy number.

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

It is a cyclic number.

It is not a de Polignac number, because 1280005 - 2³ = 1279997 is a prime.

1280005 is a lucky number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1875 + ... + 2464.

It is an arithmetic number, because the mean of its divisors is an integer number (195300).

2^1280005 is an apocalyptic number.

It is an amenable number.

1280005 is a deficient number, since it is larger than the sum of its proper divisors (282395).

1280005 is an equidigital number, since it uses as much as digits as its factorization.

1280005 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4403.

The product of its (nonzero) digits is 80, while the sum is 16.

The square root of 1280005 is about 1131.3730596050. The cubic root of 1280005 is about 108.5768460395.

Adding to 1280005 its reverse (5000821), we get a palindrome (6280826).

It can be divided in two parts, 128000 and 5, that multiplied together give a square (640000 = 800²).

The spelling of 1280005 in words is "one million, two hundred eighty thousand, five".