1311280 has 40 divisors (see below), whose sum is σ = 3138192. Its totient is φ = 509184.

The previous prime is 1311263. The next prime is 1311287. The reversal of 1311280 is 821131.

It is a tau number, because it is divible by the number of its divisors (40).

It is a Harshad number since it is a multiple of its sum of digits (16).

It is not an unprimeable number, because it can be changed into a prime (1311287) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (5) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2739 + ... + 3181.

2^1311280 is an apocalyptic number.

1311280 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 1311280, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1569096).

1311280 is an abundant number, since it is smaller than the sum of its proper divisors (1826912).

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

1311280 is a wasteful number, since it uses less digits than its factorization.

1311280 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 493 (or 487 counting only the distinct ones).

The product of its (nonzero) digits is 48, while the sum is 16.

The square root of 1311280 is about 1145.1113482976. Note that the first 3 decimals coincide. The cubic root of 1311280 is about 109.4540440865.

The spelling of 1311280 in words is "one million, three hundred eleven thousand, two hundred eighty".