1821056 has 32 divisors (see below), whose sum is σ = 3727080. Its totient is φ = 885760.

The previous prime is 1821037. The next prime is 1821067. The reversal of 1821056 is 6501281.

It is a tau number, because it is divible by the number of its divisors (32).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5075 + ... + 5421.

2^1821056 is an apocalyptic number.

1821056 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 1821056, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1863540).

1821056 is an abundant number, since it is smaller than the sum of its proper divisors (1906024).

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

1821056 is an equidigital number, since it uses as much as digits as its factorization.

1821056 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 402 (or 390 counting only the distinct ones).

The product of its (nonzero) digits is 480, while the sum is 23.

The square root of 1821056 is about 1349.4650792073. The cubic root of 1821056 is about 122.1165239839.

The spelling of 1821056 in words is "one million, eight hundred twenty-one thousand, fifty-six".