1781056 has 28 divisors (see below), whose sum is σ = 3744468. Its totient is φ = 837632.

The previous prime is 1781053. The next prime is 1781057. The reversal of 1781056 is 6501871.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 614656 + 1166400 = 784^2 + 1080^2 .

It is an Ulam number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1781053) 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, 270 + ... + 1906.

It is an arithmetic number, because the mean of its divisors is an integer number (133731).

2^1781056 is an apocalyptic number.

1781056 is a gapful number since it is divisible by the number (16) 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 1781056, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1872234).

1781056 is an abundant number, since it is smaller than the sum of its proper divisors (1963412).

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

1781056 is a wasteful number, since it uses less digits than its factorization.

1781056 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1666 (or 1656 counting only the distinct ones).

The product of its (nonzero) digits is 1680, while the sum is 28.

The square root of 1781056 is about 1334.5621004659. The cubic root of 1781056 is about 121.2157886971.

The spelling of 1781056 in words is "one million, seven hundred eighty-one thousand, fifty-six".