1999816 has 64 divisors (see below), whose sum is σ = 4798080. Its totient is φ = 760320.

The previous prime is 1999799. The next prime is 1999817. The reversal of 1999816 is 6189991.

1999816 is digitally balanced in base 5, because in such base it contains all the possibile digits an equal number of times.

It is not an unprimeable number, because it can be changed into a prime (1999817) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 29815 + ... + 29881.

It is an arithmetic number, because the mean of its divisors is an integer number (74970).

2^1999816 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 1999816, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2399040).

1999816 is an abundant number, since it is smaller than the sum of its proper divisors (2798264).

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

1999816 is a wasteful number, since it uses less digits than its factorization.

1999816 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 134 (or 130 counting only the distinct ones).

The product of its digits is 34992, while the sum is 43.

The square root of 1999816 is about 1414.1485070529. The cubic root of 1999816 is about 125.9882411131.

The spelling of 1999816 in words is "one million, nine hundred ninety-nine thousand, eight hundred sixteen".