1821456 has 120 divisors (see below), whose sum is σ = 6319040. Its totient is φ = 476928.

The previous prime is 1821433. The next prime is 1821481. The reversal of 1821456 is 6541281.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 13035 + ... + 13173.

2^1821456 is an apocalyptic number.

1821456 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 1821456, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3159520).

1821456 is an abundant number, since it is smaller than the sum of its proper divisors (4497584).

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

1821456 is a wasteful number, since it uses less digits than its factorization.

1821456 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 173 (or 164 counting only the distinct ones).

The product of its digits is 1920, while the sum is 27.

The square root of 1821456 is about 1349.6132779430. The cubic root of 1821456 is about 122.1254644070.

The spelling of 1821456 in words is "one million, eight hundred twenty-one thousand, four hundred fifty-six".