1280344240 has 80 divisors (see below), whose sum is σ = 3432333888. Its totient is φ = 435068928.

The previous prime is 1280344213. The next prime is 1280344253. The reversal of 1280344240 is 424430821.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (80).

It is a super-3 number, since 3×1280344240³ (a number of 28 digits) contains 333 as substring.

It is a Harshad number since it is a multiple of its sum of digits (28).

It is a junction number, because it is equal to n+sod(n) for n = 1280344199 and 1280344208.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 53164 + ... + 73396.

Almost surely, 2^1280344240 is an apocalyptic number.

1280344240 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1280344240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1716166944).

1280344240 is an abundant number, since it is smaller than the sum of its proper divisors (2151989648).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1280344240 is a wasteful number, since it uses less digits than its factorization.

1280344240 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20366 (or 20360 counting only the distinct ones).

The product of its (nonzero) digits is 6144, while the sum is 28.

The square root of 1280344240 is about 35781.8982168358. The cubic root of 1280344240 is about 1085.8643724053.

The spelling of 1280344240 in words is "one billion, two hundred eighty million, three hundred forty-four thousand, two hundred forty".