1280409 has 8 divisors (see below), whose sum is σ = 1838592. Its totient is φ = 787920.

The previous prime is 1280407. The next prime is 1280417. The reversal of 1280409 is 9040821.

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

It is not a de Polignac number, because 1280409 - 2¹ = 1280407 is a prime.

It is a Smith number, since the sum of its digits (24) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is an Ulam number.

It is a plaindrome in base 16.

It is not an unprimeable number, because it can be changed into a prime (1280401) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 16377 + ... + 16454.

It is an arithmetic number, because the mean of its divisors is an integer number (229824).

2^1280409 is an apocalyptic number.

It is an amenable number.

1280409 is a deficient number, since it is larger than the sum of its proper divisors (558183).

1280409 is a wasteful number, since it uses less digits than its factorization.

1280409 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 32847.

The product of its (nonzero) digits is 576, while the sum is 24.

The square root of 1280409 is about 1131.5515896326. The cubic root of 1280409 is about 108.5882679823.

The spelling of 1280409 in words is "one million, two hundred eighty thousand, four hundred nine".