199880018 has 18 divisors (see below), whose sum is σ = 325079919. Its totient is φ = 92132352.

The previous prime is 199880003. The next prime is 199880069. The reversal of 199880018 is 810088991.

It is a happy number.

It can be written as a sum of positive squares in 5 ways, for example, as 15816529 + 184063489 = 3977^2 + 13567^2 .

It is an ABA number since it can be written as A⋅B^A, here for A=2, B=9997.

It is a Duffinian number.

It is a Curzon number.

It is an unprimeable number.

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 8 ways as a sum of consecutive naturals, for example, 259538 + ... + 260306.

Almost surely, 2^199880018 is an apocalyptic number.

199880018 is a deficient number, since it is larger than the sum of its proper divisors (125199901).

199880018 is an frugal number, since it uses more digits than its factorization.

199880018 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1566 (or 784 counting only the distinct ones).

The product of its (nonzero) digits is 41472, while the sum is 44.

The square root of 199880018 is about 14137.8929830438. The cubic root of 199880018 is about 584.6865810842.

Multiplying 199880018 by its product of nonzero digits (41472), we get a square (8289424106496 = 2879136²).

The spelling of 199880018 in words is "one hundred ninety-nine million, eight hundred eighty thousand, eighteen".