1288720 has 40 divisors (see below), whose sum is σ = 3046680. Its totient is φ = 506880.

The previous prime is 1288711. The next prime is 1288733. The reversal of 1288720 is 278821.

1288720 = 65² + 66² + ... + 160².

It can be written as a sum of positive squares in 4 ways, for example, as 43264 + 1245456 = 208^2 + 1116^2 .

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

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 7030 + ... + 7210.

It is an arithmetic number, because the mean of its divisors is an integer number (76167).

2^1288720 is an apocalyptic number.

1288720 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 1288720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1523340).

1288720 is an abundant number, since it is smaller than the sum of its proper divisors (1757960).

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

1288720 is a wasteful number, since it uses less digits than its factorization.

1288720 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 283 (or 277 counting only the distinct ones).

The product of its (nonzero) digits is 1792, while the sum is 28.

The square root of 1288720 is about 1135.2180407305. The cubic root of 1288720 is about 108.8227064777.

The spelling of 1288720 in words is "one million, two hundred eighty-eight thousand, seven hundred twenty".