1999728 has 50 divisors (see below), whose sum is σ = 5791544. Its totient is φ = 666144.

The previous prime is 1999721. The next prime is 1999733. The reversal of 1999728 is 8279991.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1999721) by changing a digit.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 525 + ... + 2067.

2^1999728 is an apocalyptic number.

1999728 is a gapful number since it is divisible by the number (18) 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 1999728, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2895772).

1999728 is an abundant number, since it is smaller than the sum of its proper divisors (3791816).

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

1999728 is a wasteful number, since it uses less digits than its factorization.

1999728 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1563 (or 1548 counting only the distinct ones).

The product of its digits is 81648, while the sum is 45.

The square root of 1999728 is about 1414.1173925810. The cubic root of 1999728 is about 125.9863930884.

The spelling of 1999728 in words is "one million, nine hundred ninety-nine thousand, seven hundred twenty-eight".