199913728 has 54 divisors (see below), whose sum is σ = 464226126. Its totient is φ = 85671936.

The previous prime is 199913711. The next prime is 199913741. The reversal of 199913728 is 827319991.

It can be written as a sum of positive squares in only one way, i.e., 183656704 + 16257024 = 13552^2 + 4032^2 .

It is a Harshad number since it is a multiple of its sum of digits (49).

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 4576 + ... + 20512.

Almost surely, 2^199913728 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 199913728, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (232113063).

199913728 is an abundant number, since it is smaller than the sum of its proper divisors (264312398).

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

199913728 is an equidigital number, since it uses as much as digits as its factorization.

199913728 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15967 (or 15946 counting only the distinct ones).

The product of its digits is 244944, while the sum is 49.

The square root of 199913728 is about 14139.0851189177. The cubic root of 199913728 is about 584.7194485963.

The spelling of 199913728 in words is "one hundred ninety-nine million, nine hundred thirteen thousand, seven hundred twenty-eight".