1285440 has 112 divisors (see below), whose sum is σ = 4437888. Its totient is φ = 313344.

The previous prime is 1285429. The next prime is 1285441. The reversal of 1285440 is 445821.

1285440 is nontrivially palindromic in base 14.

It is a Harshad number since it is a multiple of its sum of digits (24).

It is a self number, because there is not a number n which added to its sum of digits gives 1285440.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1285441) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 12429 + ... + 12531.

It is an arithmetic number, because the mean of its divisors is an integer number (39624).

2^1285440 is an apocalyptic number.

1285440 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 1285440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2218944).

1285440 is an abundant number, since it is smaller than the sum of its proper divisors (3152448).

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

1285440 is a wasteful number, since it uses less digits than its factorization.

1285440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 136 (or 126 counting only the distinct ones).

The product of its (nonzero) digits is 1280, while the sum is 24.

The square root of 1285440 is about 1133.7724639450. The cubic root of 1285440 is about 108.7303042677.

The spelling of 1285440 in words is "one million, two hundred eighty-five thousand, four hundred forty".