1820816 has 20 divisors (see below), whose sum is σ = 3642624. Its totient is φ = 880800.

The previous prime is 1820813. The next prime is 1820821. The reversal of 1820816 is 6180281.

1820816 is an admirable number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1820813) 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, 1340 + ... + 2331.

2^1820816 is an apocalyptic number.

1820816 is a gapful number since it is divisible by the number (16) formed by its first and last digit.

It is an amenable number.

1820816 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

1820816 is a wasteful number, since it uses less digits than its factorization.

1820816 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3710 (or 3704 counting only the distinct ones).

The product of its (nonzero) digits is 768, while the sum is 26.

The square root of 1820816 is about 1349.3761521533. The cubic root of 1820816 is about 122.1111591016. Note that the first 4 decimals are identical.

The spelling of 1820816 in words is "one million, eight hundred twenty thousand, eight hundred sixteen".