1288640 has 28 divisors (see below), whose sum is σ = 3069336. Its totient is φ = 515328.

The previous prime is 1288613. The next prime is 1288643. The reversal of 1288640 is 468821.

It is a plaindrome in base 14.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1288643) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1694 + ... + 2333.

2^1288640 is an apocalyptic number.

1288640 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1288640 is an abundant number, since it is smaller than the sum of its proper divisors (1780696).

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

1288640 is an equidigital number, since it uses as much as digits as its factorization.

1288640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4044 (or 4034 counting only the distinct ones).

The product of its (nonzero) digits is 3072, while the sum is 29.

The square root of 1288640 is about 1135.1828046619. The cubic root of 1288640 is about 108.8204546318.

The spelling of 1288640 in words is "one million, two hundred eighty-eight thousand, six hundred forty".