999728380 has 120 divisors (see below), whose sum is σ = 2484599040. Its totient is φ = 337841280.

The previous prime is 999728321. The next prime is 999728381. The reversal of 999728380 is 83827999.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (999728381) by changing a digit.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 5234085 + ... + 5234275.

It is an arithmetic number, because the mean of its divisors is an integer number (20704992).

Almost surely, 2^999728380 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 999728380, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1242299520).

999728380 is an abundant number, since it is smaller than the sum of its proper divisors (1484870660).

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

999728380 is a wasteful number, since it uses less digits than its factorization.

999728380 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 337 (or 314 counting only the distinct ones).

The product of its (nonzero) digits is 1959552, while the sum is 55.

The square root of 999728380 is about 31618.4816207230. The cubic root of 999728380 is about 999.9094518013.

The spelling of 999728380 in words is "nine hundred ninety-nine million, seven hundred twenty-eight thousand, three hundred eighty".