1281040 has 40 divisors (see below), whose sum is σ = 3035520. Its totient is φ = 502656.

The previous prime is 1281029. The next prime is 1281041. The reversal of 1281040 is 401821.

It is a happy number.

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 an Ulam number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1281041) 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 7 ways as a sum of consecutive naturals, for example, 5241 + ... + 5479.

It is an arithmetic number, because the mean of its divisors is an integer number (75888).

2^1281040 is an apocalyptic number.

1281040 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 1281040, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1517760).

1281040 is an abundant number, since it is smaller than the sum of its proper divisors (1754480).

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

1281040 is a wasteful number, since it uses less digits than its factorization.

1281040 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 319 (or 313 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 16.

The square root of 1281040 is about 1131.8303759840. The cubic root of 1281040 is about 108.6061028941.

Adding to 1281040 its reverse (401821), we get a palindrome (1682861).

The spelling of 1281040 in words is "one million, two hundred eighty-one thousand, forty".