1287680 has 40 divisors (see below), whose sum is σ = 3093552. Its totient is φ = 514048.

The previous prime is 1287661. The next prime is 1287683. The reversal of 1287680 is 867821.

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 (32).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1287683) by changing a digit.

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 3 ways as a sum of consecutive naturals, for example, 2309 + ... + 2811.

2^1287680 is an apocalyptic number.

1287680 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 1287680, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1546776).

1287680 is an abundant number, since it is smaller than the sum of its proper divisors (1805872).

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

1287680 is an frugal number, since it uses more digits than its factorization.

1287680 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 526 (or 510 counting only the distinct ones).

The product of its (nonzero) digits is 5376, while the sum is 32.

The square root of 1287680 is about 1134.7598864958. The cubic root of 1287680 is about 108.7934252082.

The spelling of 1287680 in words is "one million, two hundred eighty-seven thousand, six hundred eighty".