199890306 has 108 divisors (see below), whose sum is σ = 554064966. Its totient is φ = 51891840.

The previous prime is 199890283. The next prime is 199890307. The reversal of 199890306 is 603098991.

It can be written as a sum of positive squares in only one way, i.e., 198556281 + 1334025 = 14091^2 + 1155^2 .

It is a super-2 number, since 2×199890306² = 79912268865547272, which contains 22 as substring.

It is a Smith number, since the sum of its digits (45) coincides with the sum of the digits of its prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (199890307) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 53 ways as a sum of consecutive naturals, for example, 105786 + ... + 107658.

Almost surely, 2^199890306 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 199890306, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (277032483).

199890306 is an abundant number, since it is smaller than the sum of its proper divisors (354174660).

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

199890306 is a wasteful number, since it uses less digits than its factorization.

199890306 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1917 (or 1896 counting only the distinct ones).

The product of its (nonzero) digits is 104976, while the sum is 45.

The square root of 199890306 is about 14138.2568232438. The cubic root of 199890306 is about 584.6966123560.

The spelling of 199890306 in words is "one hundred ninety-nine million, eight hundred ninety thousand, three hundred six".