199918551 has 24 divisors (see below), whose sum is σ = 321527424. Its totient is φ = 108222480.

The previous prime is 199918549. The next prime is 199918559. The reversal of 199918551 is 155819991.

It is not a de Polignac number, because 199918551 - 2¹ = 199918549 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 199918551.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (199918559) 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 23 ways as a sum of consecutive naturals, for example, 5605 + ... + 20766.

It is an arithmetic number, because the mean of its divisors is an integer number (13396976).

Almost surely, 2^199918551 is an apocalyptic number.

199918551 is a deficient number, since it is larger than the sum of its proper divisors (121608873).

199918551 is a wasteful number, since it uses less digits than its factorization.

199918551 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 26419 (or 26400 counting only the distinct ones).

The product of its digits is 145800, while the sum is 48.

The square root of 199918551 is about 14139.2556734787. The cubic root of 199918551 is about 584.7241507567.

The spelling of 199918551 in words is "one hundred ninety-nine million, nine hundred eighteen thousand, five hundred fifty-one".