198991728 has 240 divisors, whose sum is σ = 647069696. Its totient is φ = 58786560.

The previous prime is 198991711. The next prime is 198991729. The reversal of 198991728 is 827199891.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (198991729) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 1566801 + ... + 1566927.

Almost surely, 2^198991728 is an apocalyptic number.

198991728 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 198991728, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (323534848).

198991728 is an abundant number, since it is smaller than the sum of its proper divisors (448077968).

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

198991728 is a wasteful number, since it uses less digits than its factorization.

198991728 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 194 (or 176 counting only the distinct ones).

The product of its digits is 653184, while the sum is 54.

The square root of 198991728 is about 14106.4427833526. The cubic root of 198991728 is about 583.8191564903.

The spelling of 198991728 in words is "one hundred ninety-eight million, nine hundred ninety-one thousand, seven hundred twenty-eight".