1281824 has 24 divisors (see below), whose sum is σ = 2587788. Its totient is φ = 624640.

The previous prime is 1281823. The next prime is 1281827. The reversal of 1281824 is 4281821.

It can be written as a sum of positive squares in 2 ways, for example, as 1281424 + 400 = 1132^2 + 20^2 .

It is a nude number because it is divisible by every one of its digits.

It is a junction number, because it is equal to n+sod(n) for n = 1281793 and 1281802.

It is not an unprimeable number, because it can be changed into a prime (1281821) 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, 824 + ... + 1800.

2^1281824 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1281824, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1293894).

1281824 is an abundant number, since it is smaller than the sum of its proper divisors (1305964).

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

1281824 is an equidigital number, since it uses as much as digits as its factorization.

1281824 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1028 (or 1020 counting only the distinct ones).

The product of its digits is 1024, while the sum is 26.

The square root of 1281824 is about 1132.1766646597. The cubic root of 1281824 is about 108.6282541203.

Subtracting from 1281824 its product of digits (1024), we obtain a triangular number (1280800 = T₁₆₀₀).

The spelling of 1281824 in words is "one million, two hundred eighty-one thousand, eight hundred twenty-four".