1280039 has 4 divisors (see below), whose sum is σ = 1288056. Its totient is φ = 1272024.

The previous prime is 1280023. The next prime is 1280101. The reversal of 1280039 is 9300821.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 1280039 - 2⁴ = 1280023 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1279996 and 1280023.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1286039) 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, 3764 + ... + 4089.

It is an arithmetic number, because the mean of its divisors is an integer number (322014).

2^1280039 is an apocalyptic number.

1280039 is a deficient number, since it is larger than the sum of its proper divisors (8017).

1280039 is an equidigital number, since it uses as much as digits as its factorization.

1280039 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8016.

The product of its (nonzero) digits is 432, while the sum is 23.

The square root of 1280039 is about 1131.3880854950. The cubic root of 1280039 is about 108.5778073848.

The spelling of 1280039 in words is "one million, two hundred eighty thousand, thirty-nine".